no better success then I had had before So that the Argument may be plausibly enough retorted upon them that urge it 19. And in case the Trial should succeed sometime or other for that it doth not ordinarily I have shown already yet will there be no necessity of deriving the effects from Antiperistasis For though in such cases the fire would contribute to the production of the effect by hastening the dissolution of the snow yet the heat of the fire does but remotely and by accident cause the production of ice since other Agents will do the same thing that are qualified to make a quick dissolution of the snow whether they be hot or no as I have tri'd that spirit and crude salt of Nitre will either of them by a due application bring snow by dissolving it to congeal water though the Spirit and the Nitre be generally agreed upon to actually cold and one if not both of them to be potentially cold too 20. Having thus dispatch'd the Experiments pretended to evince an Antiperistasis I must now examine the Observations that are alledg'd to that purpose of which the principal if not the only are these The coldness of the middle Region of the Air. The increase of mens stomacks in Winter The generation of Hail and the heat and cold in Cellars and other Subterraneal places when the contrary Quality reigns in the Air. 21. To begin with the first of these I will not now dispute whether the second Region of the Air have really that coldness that is wont to be ascrib'd to it Though our Friend Mr. Boyle seems to doubt whether that Regions being always and every where cold have been as strongly proved as asserted But passing over that Question I see no need of imploring the help of Antiperistasis to keep the second Region of the Air for the most part cool For without at all taking in the cause imagin'd by the Schools an obvious and sufficient one may be easily assign'd For the Air being as to sense cold of its own nature so that when we feel it hot it is made so by some adventitious agent and that agent being for the most part the Sun who heats the Air chiefly though not only by its reflected beams their heat is so languid by that time they arrive dispers'd at the second Region of the Air that they are not able to overpower its Natural coldness increased perchance by some frigorifick spirits that may find a more commodious harbour there then in other parts of the Atmosphere And whatever be the true cause of the coldness in the middle region of the Air I cannot but admire to find that Coldness so 〈◊〉 ascrib'd to Antiperistasis by Themistius and his Friends the Aristotelians For according to them 't is the Nature of the Element of Air to be as well hot as moist and according to the same Peripateticks both the upper Region of the Air always and the lower in Summer is hot the former by the neighbourhood of the imaginary Element of fire and the latter by the reflection of the Sun-beams from the Earth which two Positions being laid together I would fain learn of any Aristotelian how Antiperistasis comes to take place here For according to them those Bodies have their cold and heat increas'd by Antiperistasis that are on both hands assail'd by Bodies of a contrary Quality to that which is natural to the surrounded Body whereas the whole Element of Air and consequently the middle Region being as they would perswade us hot of its own Nature what shadow of probability is there that the highest and lowest Regions by being hot should make the middle Region which is also naturally hot intensly and durably cold But though the objection is so clear that it needs not to be insisted on yet because 't is but an Argument ad hominem I shall add this for their sakes that are not in this point Peripateticks That it does not appear to me that if the Air be naturally rather cold then hot the second Region must owe the Intensness of that Quality to Antiperistasis For the ground of the opinion I oppose being this That both the first and the third Regions are considerably hot I would gladly find it prov'd as to the upper Region I confess I have not found the assertion contradicted but that as little convinces me as the uncontrouledness of the Tradition about quick-Lime that I lately confuted 'T is true there are two reasons alledged to evince the heat of the supreme Region of the Air but neither of them to me seems cogent For the first is that the Vicinity of this Region to the Element of fire makes it partake a high degree of Heat But if we consider the distance of that Element which they place contiguous to the Orb of the Moon and how little nearer to it the concave part of the upper Region is then the Convex of the middle we may easily conceive that in two distances that are both of them so immense so small a disparity cannot be much if at all more considerable then the greater nearness of one side of a sheet of paper held at three yards distance from an ordinary fire in comparison of the distance of the other side of the same paper or then the distances of a small Wart and of the neighbouring parts of the face when a man comes within 2. or 3. yards of the fire But 't is not worth while to prosecute this Consideration because the Argument against which 't is alledg'd is built upon the groundless supposition of the Element of fire a figment which many of themselves do dayly grow asham'd of as indeed its existence is as little to be discovered by reason as perceiv'd by sense 22. The other Argument for the heat of the third Region of the Air is that fiery Meteors are kindled by it But not now to question whether all Meteors that shine and therefore pass for fiery are really kindled exhalations we see that in the lower Region of the Air and in Winter those fires that are called either Helena or Castor and Pollux are generated in great storms and hang about the sails and shrouds of Ships Nay do not we much more frequently see that Lightning is produced at all seasons of the year for in warmer Countries thousands have observed it to thunder and so have I in Winter in the middle region of the Air. And since 't is not the heat of the inferior part of the Air that kindles those Exhalations and if notwithstanding the Coldness of the second Region fiery Meteors may be frequently generated there I see no reason why the Production of such Meteors should argue the heat of the third Region of the Air. And if that Region be not hot then it will I presume be easily granted that the coldness of the second must very improperly be attributed to such an Antiperistasis as it is generally ascribed to 23. I come next to consider
he inform'd me that it was their usual way to turn water and snow into ice by pouring a convenient Proportion of that liquor into a great quantity of snow and having also inquir'd 〈◊〉 ice had not the like operation he told 〈◊〉 that t was usual and he had seen it practis'd in 〈◊〉 to cement Ice to Buildings and other things and also to case over Bodies as it were with Ice by gradually throwing water upon them But I doubt whether that Effect be to be ascrib'd barely to the Contiguity of the Ice because I learn'd of him that this way of increasing ice is practis'd in very frosty weather when water thinly spread upon almost any other Body would be frozen by the vehement sharpness of the Air. 7. The Glaciations that nature unguided by Art is wont to make beginning at those parts of Bodies at which they are expos'd to the Air it usually happens that they freez from the upper towards the lower parts But how far in Earth and Water the most considerable Bodies that are subject to be frozen the frost will pierce downwards though for some hints it would afford worth the knowing is not easie to be defin'd because the deepness of the frost may be much varied by the degree of Coldness in the Air by which the Glaciation seems to be produc'd as also by the greater or 〈◊〉 Duration of the frost by the looser or closer texture of the Earth by the nature of the Juices wherewith the Earth is imbu'd and by the constitution of the subjacent and more internal parts of the Earth some of which send up either actually warm or potentially hot and resolving steams such as those that make corrosive liquors in the bowels of the Earth so that the frost will not seiz upon or at least cannot continue over Mines and I have seen good large scopes of land where vast quantities of good Lime-stone lay near the surface of the Earth on which I have been assur'd by the Inhabitants that the snow will not lye There are divers other things that may vary the depth to which the frost can penetrate into the ground I say into the ground because in most cases it will pierce deeper into the water But yet that we may not leave this part of the History of Cold altogether uncontributed to we will add some of our Notes whereby it will appear that in our Climate the 〈◊〉 〈◊〉 〈◊〉 less into the ground then many are pleas'd to think 8. The notes I find about this matter are these that follow which I 〈◊〉 unaltered because 't were tedious and not worth while to add the way we imploy'd and the cautions we us'd in making the observations but we shall rather intimate that the following trials were made in a Village about two miles from a great City I. Jan. 22. After four nights of frost that was taken notice of for very hard we went into an Orchard where the ground was level and not covered with grass and found by digging that the frost had scarce pierc'd into the ground three inches and a half And in a Garden nearer the house we found not the Earth to be frozen more then two inches beneath its surface II. Nine or ten nights successive frost froze the grasless ground in the Garden about six inches and a half or better in depth and the grasless ground in the Orchard where a wall 〈◊〉 it from the south Sun to the 〈◊〉 of about eight inches and a half or better February the 9. we digg'd in an Orchard near a wall that respects the North and found the frost to have 〈◊〉 the ground 〈◊〉 a foot and two inches at least above a foot 〈◊〉 〈◊〉 the eight day since it was 〈◊〉 〈◊〉 inches and a half A slender pipe of glass about 18. inches long and seal'd at one end was thrust over night into a hole purposely made with a Spit straight down into the ground the 〈◊〉 of the water being in the same level with that of the Earth the next morning the Tube being taken out the water appear'd frozen in the whole Capacity of the Cylinder but a little more then three inches But from this stick of ice there reach'd downwards a part of a Cylinder of ice of about six inches in length the rest of the water remain'd 〈◊〉 though it were an exceeding sharp night preceded by a Constitution of the Air that had been very lasting and very bitter The Earth in the Garden where this Trial was made we guess'd to be frozen eight or ten inches deep as it was in another place about the same house But is this Tube had not been in the ground the ambient Air would have frozen it quite through 9. Another Note much of the same import we find in another place of our Collections Finding that by reason of the mildness of our Climate I was scarce to hope for any much deeper Congelation of the Earth or Water I appli'd my self to inquire of an Ingenious Man that had been at Musco whether he had observed any thing there to my present purpose as also to find in Captain James's Voyage whether that inquisitive Navigator had taken notice of any thing that might inform me how far the Cold was able to freeze the Earth or Water in the Island of Charleton where that Quality may probably be supposed to have had as large a sphere of Activity as in almost any part of the habitable world And by my Inquiries I 〈◊〉 that even in frozen Regions themselves a congealing degree of Cold pierces nothing near so deep into the Earth and Sea as one would imagine For the Traveller I spoke with told me that in a Garden in Musco where he took notice of the thing I inquir'd about he found not the ground to be frozen much above two foot deep And in Captain James's Journal the most that I find and that too where he gives an Account of the prodigiously tall ice they had in January concerning the piercing of the frost into the ground is this that The ground at tenfoot deep was frozen Whence by the way we may gather how much sharper Cold may be presum'd to have reigned in that Island then even in Russia And as for the freezing of the water He does in another place occasionally give us this memorable Account of it where He relates the manner of the breaking up the Ice in the frozen Sea that surrounds the Island we have been speaking of It is first to be noted says he that it doth not freez naturally above six foot the rest is by accident such is that Ice that you may see here six fathome thick This we had manifest proof of by our digging the Ice out of the Ship and by digging to our Anchors before the Ice broke up The rest of that account not concerning our present purpose I forbear to annex only taking notice that notwithstanding our lately mention'd Experiment of freezing water in
hath taught me preserve ice and snow for a very long time Appendix to the XVI Title AN eminent instance to confirm what is delivered at the close of the foregoing Section is afforded us by the conservatories wherein snow and ice are kept all the Summer long Of these I have seen in Italy and elsewhere but supposing I had the command of some Italian and other books wherein I should meet with the dimensions and other circumstances that belong to them my finding my expectation disappointed by those books makes me think it very well worth while to subjoyn somewhat about things that may give us opportunity of making a multitude of Experiments about Cold. And therefore meeting the other day by good chance with my ingenious friend Mr. J. Evelyn his inquisitive travels and his insight into the more polite kinds of knowledge and particularly Architecture made me desire and expect of him that account of the Italian way of making conservatories of snow that I had miss'd of in several Authors and having readily obtain'd my desire of him I shall not injure so justly esteem'd a style as his to deliver his description in any other words then those ensuing ones wherein I received it from him The snow Pits in Italy c. are sunk in the most solitary and cool'd places commonly at the foot of some mountain or elevated ground which may best protect them from the Meridional and Occidental Sun 25. foot wide at the orifice and about 50. in depth is esteem'd a competent Proportion And though this be excavated in a Conical form yet it is made flat at the bottom or point The sides of the Pit are so joyc'd that boards may be nail'd upon them very closely joynted His Majesties at Greenwich newly made on the side of the Castle-hill is as I remember steen'd with Brick and hardly so wide at the mouth About a yard from the bottom is fix'd a strong Frame or Tressle upon which lies a kind of woodden grate the top or cover is double thatch'd with Reed or Straw upon a copped frame or roof in one of the sides whereof is a narrow door-case hipped on like the top of a Dormer and thatch'd and so it is complete To conserve Snow They lay clean Straw upon the grate or wattle so as to keep the Snow from running through whilest they beat it to a hard cake of an icy consistence which is near one foot thick upon this they make a layer of straw and on that snow beaten as before and so continue a bed of straw and a bed of snow S. S. S. till the pit be full to the brim Finally they lay Straw or Reed for I remember to have seen both a competent thickness over all and keep the door lock'd This grate is contriv'd that the snow melting by any accident in laying or extraordinary season of weather may drain away from the mass and sink without stagnating upon it which would accelerate the Dissolution and therefore the very bottom is but slightly steen'd Those who are most circumspect and curious preserve a tall Circle of shady trees about the pit which may rather shade then drip upon it Thus far this learned Gentlemans account of Conservatories of Snow And on this occasion I might add what the Dutch in their Nova Zembla Voyage relate namely that the three and twentieth of June though it were fair Sunshiny weather yet the heat was not so strong as to melt the Snow to afford them water to drink and that in spight of their being reduc'd to put Snow into their mouths to melt it down into their throats they were compelled to indure great thirst But because it was in so cold a Climate that this duration of the Snow was observ'd I shall rather take notice that in the Alps and other high mountains even of warmer Climates though the snow doth partly melt towards the end of Summer yet in some places where the reflection of the Sun beams is less considerable the tops will even then remain covered with snow as we among many others have in those Countries observed And for further confirmation of the Doctrine deliver'd at the end of this 16. Title I shall subjoyn a Passage which having unexspectedly met with in an unlikely place of Captain James's Voyage I think not fit to leave unmention'd here not only because 't is the sole artificial observation that I yet met with concerning the lasting of ice and so may recommend to us the Ingenuity of an Author whose Testimony we somewhat frequently make use of but because the observation is in it self remarkable and notwithstanding the difference of places may serve for the purpose we alledge it Our Navigators words are these I have in July and in the beginning of August taken some of the Ice into the ship and cut it square two foot and put it into the Boat where the Sun did shine on it with a very strong reflex about it And notwithstanding the warmth of the Ship for we kept a good fire and our breathings and motions it would not melt in eight or ten days And it is also considerable to our present purpose what the same Author elsewhere has about the durableness of the Congelation of the ground not yet thaw'd at the beginning of June For the ground says he was yet frozen and thus much we found by experience in the burying of our men in setting up the Kings Standard towards the latter end of June and by our Well at our coming away in the beginning of July at which time upon the land for some other reasons it was very hot weather Title XVII Considerations and Experiments touching the Primum Frigidum 1. THe dispute which is the Primum Frigidum is very well known among Naturalists some contending for the Earth others for the Water others for the Air and some of the Moderns for Nitre But all seeming to agree that there is some Body or other that is of its own nature supremely Cold and by participation of which all other cold Bodies obtain that quality 2. But for my part I think that before men had so hotly disputed which is the Primum Frigidum they would have done well to enquire whether there be any such thing or no in the sense newly express'd For though I make some scruple resolutely to contradict such several Sects of Philosophers as agree in taking It for granted yet I think it may be not irrationally Question'd and that upon two or three accounts 3. For first it is disputable enough as we shall hereafter see whether cold be as they speak a positive quality or a bare privation of heat and till this question be determined it will be somewhat improper to wrangle sollicitously which may be the Primum Frigidum For if a Bodies being cold signifie no more then it s not having its insensible parts so much agitated as those of our Sensories by which we are wont to judge of tactile
with him supplied him so well with Air that he was not incommodated in point of Respiration and though he felt no other inconveniencies that might disswade his tarrying longer yet the cold was so great and troublesome that he was not able to endure it above two or three hours but was constrain'd to remount to a milder as well as a higher Region I wish'd several times he had had with him a seal'd Weather-glass for ordinary Thermometers would on that occasion have been unserviceable to prevent some little doubt that might be made whether the intense Cold he felt might not be only and chiefly in reference to his Body which might be so alter'd and dispos'd by this new Briny Ambient as to make such a disturbance in the course or texture of his Blood as that which makes Aguish persons so cold at the beginning of the fit though the temperature of the Ambient Body continue the same But this is not the only person that found the Sea Exceeding cold for I remember Beguinus relates from the mouth of a Marseillian Knight that was overseer of the Coral-fishing in the Kingdom of Tunis that having upon that coast let down a young man to feel whether Coral were hard or soft as it grew in the water when this man was come about eight fathom near the Bottom of the Sea he felt it exceeding cold To which we shall add the testimony of a sober Traveller Josephus Acosta who tells us That it is a thing remarkable that in the depth of the Ocean the water cannot be made hot by the violence of the Sun as in Rivers Finally he subjoyns even as Salt-Petre though it be of the nature of Salt hath the property to cool water even so we see by experience that in some parts and havens the salt water doth refresh the which we have observed in that of Callao where they put the water or wine which they drink into the Sea in Flaggons to be refreshed whereby we may undoubtedly find that the Ocean hath this property to temper and moderate the excessive heat For this cause we feel greater heat at Land then at Sea caeteris paribus and commonly Countries lying near the Sea are cooler then those that are farther off By all these testimonies it seems to appear that both in very cold Regions and very hot the deep parts of the Sea seem to be very Cold the Sun beams being not able to penetrate the Sea to any great depth for I remember that having enquired of the Diver I lately mentioned whether he could discern the light of the Sun at any great distance from the surface of the water he answered me that he could not but as he went down deeper and deeper so he found it darker and darker and that to a degree that would scarce have been expected in so Diaphanous a Body as water is 17. But this submarine cold if I may so call it though it be great and considerable is not so intense as to intitle water to be the primum frigidum since as cold as our Divers found it at the bottom of the Sea they did not find it cold enough to freez the water there as the Air often does at the Top. 18. The next Opinion we are to consider is that of the Stoicks of old and adopted by the generality of Modern Philosophers that are not Peripateticks who assert the Air to be the primum frigidum But being ere long more particularly to treat of the Temperature of the Air we will reserve till then to examine whether it be cold of its own nature or not but in the mean time we shall here take leave to question whether it ought to be esteem'd the primum frigidum For not to mention that Aristotle and the Schools with many other learned men think the Air so far from being the coldest of the Elements that they reckon it among the hot ones because I confels their opinion is not mine not to represent the heat of the Air in the Torrid Zone nor that by the generality of Philosophers the upper Region of the Air which is believed to make incomparably the greatest part of it is always hot and the lower Region is so too in comparison of the middle though the coldness even of this is not perhaps unquestionable not to urge any of these things I say I shall in this place mention only two observations 19. The one is that which I lately recited touching the great coldness of the water in the deeper parts of the Sea for'tis not easie to show how this great cold proceeds from that of the Air whose operation seems not as may be judg'd by that little way that frosts pierce into the moist Earth to reach very far beneath the surface of the water insomuch that Captain James who had very good opportunity to try allows not in case the Ice be not made by accumulation that the Frost pierces above two yards perpendicularly downwards from the surface of the water even in the coldest habitable Regions And this will seem the more rational if we consider that in case the coldness of the Sea proceeded constantly from the Air as such the cold would be greater near the surface where 't is contiguous to the Air then in the parts remoter from it and yet the contrary may appear by the passages lately recited 20. But if it be objected that this at best can prove no more then that the Air is not the primum frigidum notwithstanding which it may be the summum frigidum For answer I must proceed to my second Argument which will perhaps evince that it is not that neither for by the same way of arguing by which those I am now dealing with endeavour to prove the Air to be the coldest Body in the World I shall endeavour to prove that it is not so For their grand and as far as I remember their only considerable Argument is drawn from Experience which shows that water begins to freez at the Top where 't is exposed to the Air but to this vulgar Experiment I oppose that of mine which I have often mentioned already to other purposes that by an application of salt and snow I can make water that would else freez at the Top begin to freez at the Bottom or at any side I please and that much sooner then the common Air even in a sharp frosty night would be able to congeal it and when in exceeding cold weather the Ambient Nocturnal Air had reduc'd a parcel of Air purposely included in a convenient glass to as great a degree of condensation as it could I have more then once by the External application of other things been able to condense it much farther which argues that 't is not the Air as such but some adventitious frigorifick Corpuscles taking that term as I do in this Treatise in a large sense that may sometimes be mingled with it which produce the notablest degrees of
so generally acknowledg'd that I cannot imagine what should make some men deny it except it be that they find all others to confess it For though in other cases they are wont to pretend Experience for their quitting the receiv'd Opinions yet here they quit Experience it self for singularity and chuse rather to depart from the Testimony of their senses then not to depart from the Generality of Men. 2. And to evince that this is not said gratis I might observe to you That there are no less then three grand inducements that have lead both the Vulgar and Philosophers two sorts of men that seldom agree in other things to consent in the acknowledgment of Antiperistasis Authority Reason and Experience But though I think fit to name them all three yet since the first of them by having as I just now noted invited our Adversaries to dissent from the Truth is a somewhat unlikely Medium to prevail on them to acknowledge it I shall insist only on the two latter having once declar'd that I lay aside the first not as worthless in it self but needless to my cause 3. To begin then with the Arguments afforded us by Reason What can there be more agreeable to the wisdom and goodness of Nature who designing the Preservation of things is wont to be careful of fitting them with requisites for that preservation then to furnish cold and heat with that self invigorating power which each of them may put forth when 't is environ'd with its contrary For the order of the universe requiring that cold and heat should reside in those Bodies that often happen to be mingled with one another those two noble and necessary Qualities would be too often destroy'd in the particular subjects that harboured them if provident Nature had not so ordered the matter that when a Body wherein either of them resides happens to be surrounded by other Bodies wherein the contrary Quality is predominant the besieg'd Quality by retiring to the innermost parts of that which it possesses and there by recollecting its forces and as it were animating it self to a vigorous defence is intended or increased in its degree and so becomes able to resist an Adversary that would otherwise easily destroy it 4. To illustrate as well as supply this Argument drawn from Reason we shall need but to subjoyn the other afforded us by Experience which does almost every day give us not only opportunity to observe but cause to admire the effects of this self invigorating power which when occasionally exerted we call Antiperistasis And these Phaenomena ought the more to be acquiesced in because they may safely be looked upon as genuine Declarations which Nature makes of Her own accord and not as confessions extorted from Her by Artificial and compulsory Experiments when being tortured by Instruments and Engines as upon so many Racks she is forced to seem to confess whatever the Tormentors please 5. To proceed then to the spontaneous Phaenomena of Nature I was recommending we see that whereas in Summer the lowest and highest Regions of the Air are made almost unsufferable to us by their heat the cold expelled from the earth and water by the Suns scorching beams retires to the middle Region of the Air and there defends it self against the heat of the other two though in the one that Quality be assisted by the almost perpendicular reflection of the Sun-beams and in the other it 〈◊〉 rendered very confiderable by the vastness of the upper Region of the Air and its Vicinity to the Element of fire And as the cold maintains it self in the middle Region by vertue of the intensness which it acquires upon the account of Antiperistasis so the Lightning that flashes out of the Clouds is but a fire produc'd in that midle Region by the hot Exhalations penn'd up and intended in point of heat by the ambient Cold to a degree that amounts to ascension 6. But though these be unquestionably the effects of that excessive coldness yet we need not go so far as the tops of mountains to fetch proofs of our doctrine since we may find them at the bottom of our Wells For though Carneades perhaps will not yet the earth as well as the Air doth readily acknowledge the power of Antiperistasis And if the reason above alledged did not evince it our very senses would For as in Summer when the Air about us is sultry hot we find to our great refreshment that the Air in Cellars and Vaults to which the cold then retreats is eminent for the opposite Quality so in Winter when the outward Air freezes the very Lakes and Rivers where their surfaces are expos'd to it the internal Air in Vaults and Cellars in Winter which becomes the sanctuary of heat as in Summer it was of Cold is able not only to keep our Bodies from freezing but to put them into sweats And not only Wells and Springs upon the account of their resting in or coming out of the deepest parts of the earth continue fluid whilest all the waters that are contiguous to the Air are by the excessive cold hardened into ice but the water freshly drawn from such Wells feels warm or at least tepid to a mans hand put into it And as if Nature design'd men should not be able to contradict the doctrine of Antiperistasis without contradicting more then one of their own senses she has taken care that oftentimes the water that is freshly drawn out of the deeper sorts of Wells and Springs should manifestly as I have seen it smoak as if it had been but lately taken off the fire And this may be said without a Metaphor to demonstrate ad ocnlum the reality of Antiperistasis there being no other cause to which this warmth can be attributed then the retiring of the heat from the cold external Air to the lower parts of the earth and water since both these Elements themselves being naturally cold and one of them in the supreme degree the heat we are mentioning is so far from being likely to be generated in so unfit a place that if it were not very great it must be extinguished there by the coldness of the superior Air and that of the inferior parts of the Earth Eleutherius 7. That Carneades may have but one trouble to answer the Allegations to be made in favour of Antiperistasis I hope he will give me leave according to my custom of siding with either party as occasion invites me to add to the familiar Observations mentioned by Themistius some others that are less obvious For I franckly confess to you that when I consider what interest the unheeded dipositions of our own Bodies may have in the estimates we make of the degrees of cold and heat in other Bodies I should not lay much weight upon the Phaenomena that are wont to be urg'd as proofs of Antiperistasis if some instances somewhat less lyable to suspicion did not countenance the doctrine they are urg'd for I know
condens'd by Cold. The III. Discourse Containing The II. Paradox Viz. Touching the Cause of the Condensation of Air and Ascent of Water by Cold in Common Weather-glasses THough I thought here to end the Praeliminary Discourse as doubting it may be thought prolix enough already yet for confirmation of what I was lately noting about the incompleteness of the Theory of Cold and because the evincement thereof may give rise to many Trials that may inrich the History of Cold I will here subjoyn a Discourse formerly written on another Occasion For though upon that Account I am fain to leave out the beginning of It as not suted to the present Occasion yet the main Body of the Discourse may be I think not improperly annex'd to what has been already said about Weather-glasses since it examines the causes of the principal Phaenomenon of them and will perhaps help to discover the incompleteness of mens Notions about Cold by showing that the true cause ev'n of the most obvious Phaenomenon of Common Weather-glasses though almost every man thinks he understands It has not yet been sufficiently inquir'd into The discourse then that first part of It as forreign to our present purpose being omitted is as follows To prosecute our Disquisition satisfactorily it will concern us to consider upon what Account the water rises in Cold Weather and falls in Hot in common Weather-glasses whose Construction being so well known that we need not spend time to set it down we may forthwith proceed to take notice That concerning the reason why in these Weather-glasses the water or other Liquor in the shank or pipe ascends with Cold and descends with Heat there are three opinions that will deserve our Consideration The first is the common opinion of the Schools and Peripateticks and indeed of the generality of learned Men of differing Sects who teach that the Cold of the External Air contracting the Air included in the Weather-glass and thereby reducing it into a narrower Room then formerly it possest the water must necessarily ascend to fill the place deserted by the retired Air lest that space should become a vacuum which Nature abhors But against this Explication we have several things to object For first I am not satisfi'd that any of the Schoolmen or Peripateticks at least of those I have met with have solidly evinc'd that Nature cannot be brought to admit a vacuum Nor do I much exspect to see that assertion well prov'd by these or by any other that forbear to make use of the Argument of the Cartesians drawn from the Nature of a Body whose very essence they place in its having extension which I say because about this Argument I neither have yet published nor do now intend to deliver my thoughts Next it seems a way of Explicating that little becomes a Naturalist to attribute to the senseless and inanimate Body of water an Aim at the good of the Universe strong enough to make it act as if it were a free Agent contrary to the tendency of its own private Nature to prevent a Vacuum that as is presum'd would be hurtful to the Universe But these Arguments we have elsewhere urg'd and therefore need not insist longer on them here Thirdly if you take a Bolthead with a large Ball and long stem and do with that and Quicksilver make the Torricellian Experiment there will be an Instrument prepar'd like a Common Weather-glass save that the stem is longer and that the Liquor is Mercury instead of Water and yet in this case we see not that the Mercury which remains pendulous in the pipe at the height of about 30. Inches offers to ascend into the cavity of the Bolthead to fill up the space whence the Air was expell'd by the Mercury and which the Quicksilver also by its subsiding deserted And the outward application of Cold Bodies to the 〈◊〉 part of the head will not perhaps Occasion the rising of the Quicksilver a ¼ of an Inch is half so much though the like degree of Cold would make the water ascend in a Vulgar Thermometer though shorter to the height of several Inches But this Argument I also on another Occasion further display and vindicare Wherefore I shall add one more taken from the Consideration of these seal'd Weather-glasses that are describ'd in this 〈◊〉 History of Cold. For in these the Air does not shrink but rather seems to be expanded when the weather grows Colder If it be said that water being contracted by the Cold the Air follows it to prevent a Vacuum I answer that those that say this should explain why whereas in Common Weather-glasses the water ascends to follow the Air in these the Air must descend to follow the water And why since to avoid a Vacuum the one in common Weather-glasses and the other in seal'd ones resists contraction Nature does not rather make the Air in Common Thermometers retain the extension they conceive due to its nature then put her self to the double Labour of suffering the Air to be preternaturally condens'd and compelling the water to ascend contrary to its nature But these Arguments I will not urge so much as this other that in our present case the above propos'd Answer will by no means salve the difficulty For if the water be really condens'd into less and the Air expanded into more space then they respectively possest before I see not how a Vacuum or a worse Inconvenience will be avoided for I demand since Glass is granted to be impervious to Air and water as indeed else Nature would not need to make water ascend contrary to its own tendency in a Common Weather-glass what becomes of the Body that was harbour'd in the space deserted by the water upon its Condensation Which Question those that do not say any thing escaped away through the Glass or that any thing was annihilated will not easily answer But this is not all for I further demand when the Air expands it self to follow the water how by that expansion of the Air a Vacuum both coacervatum as the old Epicureans spoke and interspersum is avoided For the aerial Corpuscles cannot advance into this space deserted by the water without leaving either in whole or in part the spaces they fill'd before so that by this remove an aerial Corpuscle only changes place but does not adequately fill any more place then it did before But if it be said that the same Air without any substantial Accession may adequately fill more space at one time then at another If this I say be pretended I shall not urge that it appears not why it were not more easie for Nature in common Weather-glasses as well as in seal'd ones to rarifie the Air which they reach to be so very easily rarifi'd and condens'd then to make the heavy Body of water to ascend For I may very well reply that I scarce know any Opinion in Natural Philosophy that to me seems more unintelligible and more worthy to be
these Weather-glasses are so exceeding sensible even of the minute Differences of Heat and Cold as manifestly to discover Disparities which other Thermoscopes are not nice enough to give us any Notice of Only this Advertisement we must add about them that when we use them to examine the Coldness not of liquid but of consistent Bodies we alter a little the figure of the wide end of the Glass and instead of maing it a round bubble as we have elsewhere describ'd we make it with a flat or flattish bottom that the whole Instrument might thereon as on a Basis stand of it self upright and so being still taken up by the open and slender end for fear of rarifying the included Air which Caution is here given once for all may be transferr'd with a pendulous drop in the Pipe and plac'd sometimes on one and sometimes on another of the solid Bodies to be examined by it For if the Body 't is removed to be more or less cold then that it rested on before that coldness communicated through the Glass to the Air by which the pendulous drop is supported that Airs Expansion or Contraction will manifestly appear by the rising or the falling of the drop And thus we have taken pleasure to remove it from one kind of wood to another from woods to metals and from metals to stones c. But the Expedients that may be propos'd to improve these little Instruments to the purposes we have been treating of and the Cautions that may be added to prevent mens drawing mistaking Inferences from the Informations they seem to give them will take up more time then we are willing to spend npon an occasion that will not perhaps be thought to deserve it nor much to require any others then those we shall by and by subjoyn And therefore I shall proceed to the Experiment promis'd at the beginning of this Title or Section 2. To make so much as a tolerable Estimate of the Difference betwixt such great Degrees as are not any of them too weak to congeal water is a thing which as we have not yet known to be attempted so it seem'd not easie to be perform'd For Freezing having been commonly reputed the ultimate Effect or Production of Cold men have not been sollicitous to look beyond it And though the Disparity we find betwixt several Fits of weather all of them frosty seem to be too manifest and frequent to be probably ascrib'd to nothing but the differing Dispositions of our Bodies yet how to estimate that Difference it is not so obvious For though we should have recourse to common Weather-glasses yet they might easily deceive us since not only by estimating by them the coldest day of one Winter with the coldest day of another but in judging of the Coldness of any two days in the same fit of frosty weather there intervenes time enough to make it doubtful whether the vari'd Gravitation of the Atmosphere produce not the change observ'd in the Weather-glass Besides that admitting vulgar Thermometers could not as they easily may misinform us they are imploy'd only to give us an Account of those degrees of Cold 〈◊〉 Nature of her own accord produces in the Air but not to discover whether or no Nature assisted by Art may not produce greater And 't will easily be granted that they are yet less made use of to help us to an Estimate of this Disparity And though some guess may be made by the operations of Cold upon Liquors expos'd to it yet some as water and very aqueous Liquors will freez too soon and others as Vinous spirits will not at all that we have found here in England And though French-Wine will sometimes be brought to begin to freez yet that happens but very seldom and in many Winters not at all and leaves too great an Interval betwixt the degrees necessary to congeal Wine and sufficient to congeal Water not to mention the uncertainty proceeding from the differing strengths of the Wines 3. Upon these and other considerations we thought it requisite to make use of an Expedient whose Nature and use will be easily gathered out of the following Experiments And though by a mischance that broke my Weather-glass I have been hindred from measuring exactly in what Proportion to the whole bulk the spirit of Wine was contracted by the surplusage of Cold that was more then necessary to make water freez yet I doubt not but something of use to our present Theme may be thence collected and especially the main thing design'd will manifestly appear which is the Intensity of Cold produc'd by Art beyond that which Nature needs to employ upon the glaciating of water 4. A small seal'd Weather-glass furnished with spirit of Wine the ball being about the bigness of a large Nutmeg and the Cylindrical stem being very slender and about ten Inches long the Ball and part of the stem being immers'd in a vessel of water half buri'd in snow and salt when the water began to freez at the top the bottom and the sides but before the Ice had reach'd the Ball for fear it should break it the tincted liquor was found subsided to 5 ⅔ Divisions being half Inches and being taken out thence and Ice and Salt being immediately appli'd to the Ball the Liquor fell lower to about 1 ½ Division And that it may not be doubted but that the water though in part congeal'd remain'd warm in comparison of the spirit of Wine though uncongeal'd that had been refrigerated by the snow and salt we will add this other Experiment which we find in another of our Notes thus set down 5. The seal'd Weather-glass being kept in the water till it began to freez descended to 5 ½ Being immediately remov'd into the same snow and salt that made the water begin to freez it descended at the beginning very fast and afterwards more slowly till it came to the very bottom of the stem where it expands it self into the Ball then being remov'd into the same glass of water whence it was taken and which was well stor'd with loose Pieces of Ice it did nevertheless hastily ascend at the beginning and was soon after impell'd to the former Height of five Divisions and an half or thereabouts 6. But perhaps some amends may be made for the disaster of the Weather-glass by adding that I found by another Trial that the Condensation of Liquors by such Colds as we are wont to have or can easily produce here is nothing near so great as one would imagine And though for want of a Glass-ball furnish'd with a neck slender enough I could not make the Experiment so much to my satisfaction as perhaps else I might have done yet the goodness of the scales I made use of and some greater care then possibly every Experimenter would have imploy'd may make the following Observation Luciferous 7. We took then on a cold but not frosty day oyl of Turpentine as a Liquor whose being free from phlegm or
or Downwards 1. THough after the consideration of the sphere of Activity of Cold it would be the most proper place to take some Notice of the Direction of its Activity yet because one of the Experiments that belong to This head is of great use to facilitate the trial of many of those that follow throughout this whole Collection we will no longer delay to say something of this matter namely in what Line or if you please towards what part the frigefactive vertue of cold Bodies does operate the furthest and the most strongly 2. 'T is a Known Doctrine among Philosophers that the Diffusion of Heat tends chiefly upwards as the flame of a Candle will burn many things held over it at a greater Distance then it would considerably warm them at in case they were held beneath its level or even by its sides and 't is true that in all cases vulgarly taken notice of the observation for reasons elsewhere discoursed of holds well enough and therefore it may be worth enquiry whether in Cold which is generally looked upon as the contrary Quality to Heat the diffusion from cold bodies be made more strongly downwards then either upwards or towards the sides About this matter I can as yet find among my Notes but the two following Experiments 〈◊〉 those not both together A very thin bubble was blown at a Lamp and purposely made flat at the bottom that it might be the more exposed to the cold and it was suspended by a string within a pretty deal less then an inch of a mixture of beaten Ice and Salt wherewith we had half fill'd a conveniently large wide-mouth'd glass but we could not find that a cold Capable of freezing did strike so high upwards for the water in the bubble remained altogether unfrozen which agrees very well with what we have observed that a mixture of ice and salt did not 〈◊〉 the vapours that wandered through the Air above half a barley corns breadth higher then the mixture in the Glass reached 3. A mixture of snow and salt being put into a vial with a long neck the round part of it was by a weight kept under water out of which being taken after a while the outside of the glass beneath the surface of the water was cased with solid Ice N B. especially about the bottom of the vial of greater hardness and thickness then one could easily imagine 4. Thus far the notes from which nevertheless I will not positively conclude though they seem to perswade it that the tendency of the cold produced by Bodies qualified to freez others is greater downwards then upwards For the satisfactory determination of that matter may for ought I know require Trials more artificial and nice then those we have been reciting And I could wish that I could find the last of them to have been carefully repeated and registred because it seems somewhat strange that the Ice should be much thicker at the bottom of the vial then elsewhere in regard that when we have as we very frequently have put mixtures of snow and salt into vials and left them in the open Air we generally observ'd that the outside of the Glass was cas'd with Ice or covered with hoar frost directly over against that part of the inside of the Glass wherein the frigorifick mixture was So that part of the snow and salt resolving one another and falling down in the form of a liquor to the bottom the unmelted part of the mixture would float upon this liquor and the external Ice would appear over against the floating mixture by which it was generated So that as the mixture grew thinner and thinner so would the Zone or girdle if I may so call it of external Ice grow narrower and narrower till at length when the snow was quite melted away the external Ice would quickly also vanish But from this observation which we frequently made That as in such vials 〈◊〉 Ice did not appear as I just now related above half a corns breadth higher then the mixture in the glass so I remember not to have observed it much lower beneath the mixture from those things I say it may be probably conjectured that even the coldest Bodies at least unless their Bulk alter the case do not diffuse their freezing vertue either upwards or downwards to any considerable distance 5. These trials as I was intimating may suggest some difficulties about the last of the two Experiments transcribed out of my notes But as 't is evident these observations were made in the open Air by the freezing of its roving vapours and the mentioned Experiment was made under water so how much this difference of mediums may alter the case as to the way of the Diffusion of cold I dare not till further trial boldly determine especially since one Circumstance to be under the next Title mentioned about the freezing of Eggs may pass for an addirional Experiment as to our present Enquiry For the Cases obtain'd by frozen Eggs suspended under water which seem to argue that the Diffusion of their cold was made every way since they were quite enclosed in the Ice they had produced 6. Though the Experiment of freezing water by the Intervention of salt and snow be not a new one for substance yet I hold it not amiss to make a further mention of it on this occasion Because that what I am to deliver about it is a Paticular not taken notice of that I know of by others the premising of which will according to what we lately intimated much facilitate the trial of many of the Experiments to be set down in the following part of these papers and will indeed appear to be of no small moment in our whole Attempt of Framing an History of Cold. For it has long seemed to me one of the chief things that has hindered men from making any considerable progress in this matter that whereas glass-vessels are generally much the most proper to freez liquors in because their transparency allows us to see what changes the Cold makes in the liquors exposed to it the way of freezing with salt and snow as it has been hitherto used does almost as little as the common way of barely exposing vessels to the cold Air in frosty weather prevent the unseasonable breaking of the glasses For in both these ways the water or other liquor usually beginning to freez at the top and it being the Nature of Glaciation as we shall see anon to distend the water and Aqueous liquors it hardens it is usually and naturally consequent that when the upper crust of Ice is grown thick and by reason of the Expansion of the frozen liquor bears hard with its edges against the sides of the glass contiguous to it the included Liquor that is by degrees successively turned into Ice requiring more Room then before and forcibly endeavouring to Expand it self every way finds it less difficult to burst the glass then lift up the Ice and
no pain save that when he came to himself again he felt such a pricking all his Body over as men are wont to find in an Arm or Leg benumm'd by having been long lean'd upon When I ask'd whether the sharpness of the Cold did not work upon the stones he answer'd That as to Flints he could not tell but as to other stones and such as are oftentimes us'd for Building the violence of the Cold made them frequently moulder into Dust. And to satisfie my Curiosity about the Effect of Cold upon Wood he told me that he had very often in the night especially when their keen frosts were unaccompani'd with Snow heard the Trees cleave and crack with very great and sometimes frightful noises and that the outside of the Fir-Trees that were laid upon one another in their Buildings and was expos'd to the Air would do the like and that he had often seen the gaping Clefts sometimes wide enough to put in his fingers which would remain in the Trees and in the Fir-wood till the thaw after which they would pretty well close of themselves Title VII Experiments touching the Expansion of Water and Aqueous Liquors by Freezing 1. THat water and other Liquors are condensed by Cold and so much the more condensed by how much the greater the degree of Cold is that condenses them has been for many ages generally taught by the Schools and taken for granted among men till of late some more speculative then the rest have called it in question upon the account of the levity of Ice since which I have met with two modern writers that have incidentally endeavoured to prove that Ice is water not condensed but rarified by the intumescence of water exposed to freezing in vessels fitly shap'd These Attempts of these learned Men putting me in mind of what I had tried to this purpose when I was scarce more then a Boy invited me to consider that by the usual ways of Glaciation such as these ingenious Men employ'd the Experiment is wont to meet with a Disaster by the breaking of the Glasses which not only makes the Event liable to some objections of theirs that befriend the common Opinion but which is more considerable hinders them from judging what this Expansion of water that is made by freezing may amount to wherefore we will now set down what we have done to ascertain and yet limit the Experiment as also to advance it further 2. Whereas then these two learned Men we have been mentioning do so expose the water to freez that it is turn'd into Ice at the top as soon as elsewhere the inconveniences of which way we have already noted we by freezing the water as we have formerly taught from the bottom upwards can easily preserve our Glasses entire and yet turn the whole contained water into Ice so that if according to this way You so place a Bolthead or a Glass-egg in whose Cavity the water ascends to the height of an inch or thereabouts within the stem or shank in a mixture of Ice or snow and salt as that the water is first turned into ice at the bottom and sides and not till the very last at the top you shall manifestly see that the ice will reach a good way higher in the neck then the fluid water did and that upon a gentle thaw of the ice the water it returns to will rest at the same height in the stem to which it reached before it was exposed to be frozen 3. We have likewise used other ways unspoken of by the lately mentioned writers to evince that water is expanded by being frozen as first that we took a strong earthen vessel of a Cylindrical form and filling it with water to a certain height we exposed it unstopped both to the open Air in frosty nights and to the operation of snow and salt and found that the ice did manifestly reach higher then the water did before it was congealed Besides if a hollow Pipe or Cylinder made of some compact matter be stopped at one end with wax or some things else which it may be more easie to drive out then to burst the Cylinder and if at the other end it be filled with water and that orifice also be stopped after the same manner this Pipe suspended in a sufficiently cold Air will have the included water frozen and by that change if the Experiment have been rightly made the water will upon congelation take up so much more room then it did before that the above mentioned stoppels or at least one of them will be thrust out and there will be produced a rod of Ice a good deal longer then the pipe at each of whose ends or at least at one of them a Cylindrical piece of Ice of a pretty length may be broken off without medling with the Pipe or the ice that fills it Divers other ways of proving the same Truth might be here alledged but that though these were not 〈◊〉 they are sufficient the matter would yet be abundantly confirm'd by divers of the Experiments that will here and there come in more opportunely in the following part of this Treatise 4. But here it will not be altogether impertinent or unseasonable to take notice that not only those School Philosophers who have considered the breaking of well 〈◊〉 Glasses in frosty weather an accident but too frequent in Apothecaries Shops and Laboratories but divers modern Virtuosi are wont to ascribe the Phaenomenon to this that the Cold of the external Air contracting the Air and Liquor within the Ambient Air must break the sides of the Glass to fill that space which being deserted upon the condensation of the included Air the liquor would otherwise leave a vacuum abhorr'd by nature and even those few Moderns that are loath to ascribe this Phaenomenon to Natures abhorrency of a vacuum either not being acquainted with the weight of the Air know not what probable account to give of it or if they acknowledge that weight are wont to ascribe it to that and to the great contraction of the internal Air made by the Cold of the External 5. But as for the Peripateticks the above mentioned Experiments sufficiently evince that in many cases 't is not the shrinking but the Expansion of the liquors contained in the stopt vessels that occasions their bursting and therefore in these cases we need not nor cannot fly to I know not what fuga vacui for an account of the Phaenomenon and whereas it may be objected that even glasses not half full of distill'd waters if they be exactly stopt are often broken by the frost in Apothecaries shops I answer That neither in this case do I see any need of having any recourse either to the fuga vacui or to the weight of the external Air for even here the Expansion of the freezing liquor may serve the turn for in such inartificial glaciations the liquor begins to freez at the top and the ice there
generated fastning itself as on other occasions we declare very strongly to the sides of the Glass contiguous to its edg as the liquor freezes deeper and deeper this crust of Ice increases in thickness and strength so that the water is included as in a vessel Hermetically sealed betwixt this Ice at the upper part and the sides and bottom of the Glass every where else and consequently the remaining water being uncapable of Congelation without Expansion when the ice is grown strong enough at the top to make it easier for the expansive endeavour of the freezing water to crack the sides or bottom of the Glass then to force up that thick cake of Ice the vessel will be broken how much soever there be of it empty above the surface of the Ice And this Conjecture may be confirmed by these two Particulars the one That when water is frozen in a broad vessel which is too strong to be broken or stretch'd by the frost the surface of the ice contiguous to the Air will be convex or protuberant because that though the glaciation began at the top the thickness and Compactness of the vessel makes it easier for the expansive endeavour to thrust up that cake of ice in those parts of it that are the remoter from the sides whereunto they are strongly fastned then to break so solid a vessel 6. The other Particular is afforded us by that Experiment of ours mention'd in the Vth Title foregoing wherein if a vessel half full of water be made to freez not first at the top but at the bottom that liquor may be turned into ice without danger to the glass But we will now add an Experiment on whose occasion we have set down these Considerations For being inclined to think that the spring of the Air shut up in a vessel stopped will preserve it expanded or at least keep it from considerably shrinking notwithstanding a very great degree of Cold in case the vessel be strong and close enough to fence it from the pressure of the external Air we conjectured that the bare weight of the outward Air added to the Refrigeration of the included Air would not be sufficient to break much weaker glasses then those we have been speaking of And therefore partly to satisfie some ingenious Men that this Conjecture made me dissent from and partly to show the Peripateticks and those that adhere to them in the question under consideration that either the Cold alone cannot always as they teach us contract the Air or that if it do the breaking of well stopp'd glasses in frosty weather is much fitter to evince that there may be a vacuum then that there can be none we made the following Experiment 7. We took three glass-bubbles of differing shapes and sizes which we caused to be blown with a Lamp that to make the Experiment very favourable for our Adversaries we might have them much thinner and consequently weaker then those glasses that are wont to be made use of to keep liquors in and which notwithstanding are wont to be broken though they be not full by the frost These Bubbles when the Air was at a convenient temper within were as easily they might be nimbly seal'd up with care to avoid the heating of the Air in them and being afterwards expos'd sometimes to the Air it self in very frosty weather and sometimes to that greater Cold which is produced by the placing them in a mixture of snow and salt we could not nevertheless find that any one of the three was at all broken or cracked so that in case the included Air were condensed into a lesser room the space it deserted may be concluded empty or else it will hardly appear what 〈◊〉 there can be that Nature should break as the Peripateticks pretend very much stronger glasses in Apothecaries shops to prevent a vacuum 8. Having shown that water it self acquires a considerable Expansion by Cold we will next shew that Aqueous Bodies or those that abound with waterish parts do divers if not 〈◊〉 of them the like We took Eggs and exposing them to a sufficient Degree of Cold we observ'd that when the contain'd liquors were turn'd into Ice they burst the shells asunder so that divers gaping Cracks were to be seen in them as long as they continu'd frozen 9. Milk Urine Rhenish-wine and good spirit of Wine being set to freez in distinct glass Eggs neither of the three former liquors 〈◊〉 observ'd to subside before it began to rise The Event in sum was that the Urine was much longer then either of the two other liquors before it began to swell but rose to a far greater height then they afterwards The Wine did not leave the mark above an inch beneath The Milk ascended about two inches and the Urine by guess six or seven 10. A strong solution of 〈◊〉 Vitriol being put into a Cylindrical Pipe seal'd at one end so that the liquor fill'd the Pipe to the height of about six or eight inches being frozen with snow and salt the congeal'd liquor grew very opacous and look'd as if it had been turn'd or shot into Vitriol save a little that remain'd fluid and transparent near the bottom And this Ice as appeared rose considerably higher then the liquor did before Congelation It were perhaps worth trying whether or no even several Bodies of a stable consistence and durable Texture might not be found to receive some though less manifest Dilatation by excessive Cold. And methinks those who attribute Glaciation to the plentiful Ingress of frigorifick Atoms into Bodies should by their Hypothesis have been invited to make some Trials of this kind since we see that the invisible Moisture of the Air against rainy weather does seem manifestly enough to alter the Dimensions of doors window-shuts and other such works made of wood not well season'd And even without supposing the truth of the Epicurean Hypothesis if we consider that in Bread though we are sure that much more water was added to the Meal or Flower then was exhal'd in the Oven yet there appears not the least drop of water distinct in the Concrete and that Harts-horn Sponges and many other Bodies that seem very dry will afford by distillation good store of phlegm or water and more then can probably be ascrib'd to any transmuting Operation of the Fire If I say we consider these and the like things it may seem worth while to try which I want the conveniency to do by accurate measures whether the invisible and interspers'd water its comminution notwithstanding will not upon freezing swell the Body that harbours it And I would the more gladly have been satisfi'd in this because I hop'd it might help me to unriddle a strange 〈◊〉 afforded us by the Narrative of the Dutchmens Voyage to Nova Zembla wherein they relate That the Cold was so great that their Clock was frozen and would not go though they hung more weight upon it then before So that they were
but the interspersion of such bubbles The Observations I have been mentioning I find thus set down among my Notes A piece of Ice that to the Eye look'd clear like crystal being put into the great Microscope appear'd even there free from bubbles and yet the same piece of Ice being presently remov'd and cast into common water would swim at the top and if it were forcibly duck'd would swiftly enough emerge Another piece of Ice that to the naked Eye was not so clear as the former appear'd in the same Microscope to have store of bubbles some of them appearing there no bigger then a small pins head and some of them being yet lesser and scarcely visible in the Microscope it self And here because it seems a considerable doubt and well worth the examining whether or no water when frozen into Ice grows heavier or lighter not in reference to such water as it was generated of since it is evident that upon that it will float but more absolutely speaking we judg'd it not amiss to examine this matter by an Experiment but we could not discover any difference between the weight of the same parcel of water fluid and frozen as will appear by the ninth Paragraph of the Experiment to be a little beneath recited But since that whether or no we allow any other cause together with the bubbles to the levity of Ice it seems a thing not to be doubted that its expansion and lightness is mainly if not only due to the interspersion of bubbles the generation of them seems to be one of the considerablest Phaenomena of Cold and the Investigating by what cause those cavities are produced and in case they be perfectly full what substance 't is that fills them is none of the meanest enquiries that should exercise the industry of a searcher into the Nature of Cold. 4. Mr. Hobs and some others seem to think that the expansion of water by congelation is caus'd by the Intrusion of Air which constitutes those numerous bubbles wont to be observ'd in Ice we might here demand why in case that upon freezing there must be a considerable accession of Air from without when oyl is frozen it is notwithstanding the ingress of this Air not expanded but condens'd but because these conjecturers do not allow glass to be pervious to common Air we shall at present press them with this Experiment which we have divers times made We took a glass-Egg with a long stem and filling it almost with water we seal'd it Hermetically up to exclude the pretence that some adventitious Air might get in and insinuate it self into the water and yet such an Egg being exposed to congelation the frozen water would be manifestly expanded and swell'd by numerous bubbles which oftentimes gave it a whitish opacity To which we may add that new metalline vessels being fill'd with water and carefully stopp'd the liquor would nevertheless when exposed to the Cold be thereby expanded and turned into Ice furnished with bubbles 5. If it be objected that in the Experiment of the Hermetically seal'd glass the produced bubbles might come from the Air which being seal'd up together with the water might by the expansion of that water be brought to mingle with it I answer that this is very improbable For 1. if the bubbles must cause the expansion of the water how shall the water be at first expanded to reduce the Air to a Division into bubbles Next 't is evident by the Experiments we shall ere long relate that the Air as to the Body of it retains its station above the water and preserves it self together in one parcel since it suffers a compression that oftentimes makes it break the glass that imprisons 〈◊〉 which it would not need to do in case it dispers'd it self into the Body of the water for then there would appear no cause why the Air and water should after congelation require more room then they did before 3. In this Experiment we usually begin to produce Ice and bubbles in the water contiguous to the bottom of the vessel that part being by the snow and salt first refrigerated in which case there appears no reason why the Air which is a thousand times lighter then the water should against its nature dive to the bottom of the water and if it were disposed to dive why should we not see it break through the water in bubbles as is usual in other cases where Air penetrates water 4. In metalline vessels and in Glasses quite filled with water before they are stopped there is no pretence of the diving of the Air from the top there having been none left there 5. and lastly If all the bubbles of Ice were made by and filled with true Air descending from the upper parts of the vessels and only dispersed through the water then upon the thawing of this Ice the Air would emerge and we might recover as much of real Air as would fill the space acquired by the water upon the account of its being turned into Ice which is contrary to our Experience And this Argument may also be urged against any that should pretend for I exspect not to see him prove it that though Air as numerous experiments evince cannot get out of a seal'd glass yet it may in such a case as this get into it But we find upon trials that the Cavities of these bubbles are not any thing near filled with Air if they have in them any more Air at all then that little which is wont as we have elsewhere shewn to lurk in the particles of water and other liquors And the making good of this leads us to the second Enquiry we were proposing about these bubbles namely whether or no their cavities be fill'd and fill'd with Air. 6. The full resolution of this whole Difficulty would be no easie Matter nor well to be dispatched with so much brevity as my occasions exact For it would require satisfactory Answers to more then one or two Questions since for ought I know it may lead us to the debate of those two grand Queries whether or no Nature admit a Vacuum and whether a great part of the Universe consist of a certain Ethereal matter subtile enough to pass through the pores not only of liquors but of compact bodies and even of glass it self we should also be obliged to enquire whether or no Air I mean true and permanent Air can be generated anew as well out of common water as many other liquors and whether it may be generated by Cold it self and perhaps we should be oblig'd to inquire into the Modus of this production and engage our selves in divers other difficulties whose full Prosecution besides that they would as much exceed our present leisure as Abilities seems more properly to belong to the more general part of Physicks where such kind of general Questions are fittest to be handled Wherefore we will now only consider this Particular Question whether or no the Cavities of
and spoil the other liquor was indeed sweet like rain water but so very little as well as so slowly generated that it amounted not any thing near to that which the snow imploy'd and spoil'd to make it would have afforded So that it may be question'd whether some cooling liquors which can as well as this mixture condense the vapid Air into water and whose Texture is not destroy'd in this operation as that of the snow is might not be more hopefully imploy'd to obtain water from the Air to which I shall only add this one thing That the mixture of snow and salt did turn the vapours that fasten themselves to the outside of the glass first into Ice before they dropt down in the form of water in almost all our Trials of this nature as well in thick Funnels as in other and thinner glasses 5. That in Hermetically seal'd glasses an included mixture of snow and salt will freez the vapours of the Air on the outside of the glass divers of the Experiments of the present Treatise do manifestly evince which argue that even so extremely close a Medium as Glasses is not able to hinder the Transmission of Cold. And this is not superfluously added because in vessels not Hermetically seal'd it may be pretended that 't is the internal Air that communicates its Coldness by some unheeded but immediate intercourse with the external After this we thought it worth an Experiment to try whether or how Cold would be diffused through a Medium that some would think a Vacuum and which to others would seem much less disposed to assist the Diffusion of Cold then common Air it self to compass this the Expedient we bethought our selves of was to suspend a slender glass full of water in one of the small Receivers belonging to our Pneumatical Engine and when the Air was very carefully pump'd out to bury the exhausted Receiver in a copious and ready prepar'd mixture of Ice and Salt to see whether notwithstanding the withdrawing of the Medium the water suspended in a kind of Vacuum as to Air or gross substances would yet be frozen by the Cold. That Event of our trials which alone I find among my Notes is registred in these terms 6. A small pipe seal'd at one end was at the other fill'd almost with water and was put into a Receiver consisting of a somewhat long and slender Tube of Glass seal'd at one end and inverted upon the Engine plate then the Air was carefully exhausted for the pump was ply'd a while after no Air appear'd to come forth in any bubble out of the Receiver through the external water nor did the water in the small pipe within disclose any number of bubbles worth taking notice of then by the help of an almost Cylindrical plate of Iron beaten Ice and Salt were heap'd against the outside of the Receiver about the height to which the water in the small pipe reach'd And at length though as we all thought much more slowly then such a Congelation would else have been perform'd the water was for the most part frozen in odd kind of flakes from the top to the bottom and the ice seem'd not to have any considerable number of Bubbles 7. There is one Experiment I have made about the Transmission of Cold through indispos'd Mediums which may not be unworthy to be here inserted For I had once a mind to try whether a cold Body could operate through a Medium that was as to touch actually hot and had its heat continually renew'd by a sountain as it were of heat that perpetually diffus'd through it new supplies of warm Liquor so that the cold Body could not here as in other cases first allay the heat of the Medium and then lessen it more and more till it had quite extinguish'd it To compass this I had soon after an opportunity of making some trials presented me For being at the Mineral Springs at Tunbridge to drink those wholsome waters for my healths sake I soon accustomed my self to drink them in considerable Quantities very early in the morning when they were exceeding Cold and sometimes drinking them in bed as well as sometimes at the Springs-head I had the Curiosity to observe whether in case I took them down very fast they would not through the warm Muscles and outward Parts of the Abdomen diffuse a sensible Coldness and upon more Trials then one I found that by laying my warm hands on the outside of my Belly I there felt at least as it seemed to me a manifest and considerable Degree of Coldness And when I related this to some ingenious Persons that were better acquainted with those Springs then I they told me that there was among those many that then resorted to those famous Springs a Knight whose Name I remember not whose Disease being judg'd formidable the Physicians enjoyned him to drink in a morning two or three times the Quantity that afforded me the Observation I was relating and that when this Knight had fill'd his Belly with so much water he us'd mightily to complain of the Coldness it diffus'd through his Abdomen insomuch that he was fain to ply those parts long with hot Napkins clapp'd to them one after another which yet as he complain'd were soon refrigerated by the excessive Cold that the water diffus'd to the outside of his Belly which yet nevertheless was not that I could learn at all prejudic'd no more then mine by so sensible and piercing a Cold. 8. It may be doubted whether in case water be not fluid upon the account of a congenite motion in the Corpuscles it consists of its fluidness may not proceed from the agitation of the ambient Air either immediately contiguous to the surface or communicating its agitation to the water by propagation of its Impulse through the vessel that interposes betwixt them To contribute to the clearing of this and some other things we devis'd the following Experiment We provided a glass-bubble of about the bigness of a Walnut and the form almost of a Pear whose stem was purposely made crooked for the conveniency of suspension This being fill'd with water which is troublesome enough to be done unless one have the knack we hung it at one end of a thread whose other end we past through a Cork by a perforation purposely made into which we afterwards fastned the thread by thrusting in a small peg to rivet it in Then filling a glass not very broad but yet furnished with a mouth wide enough to receive the bubble with oyl of Turpentine such as we bought it at the shops we stopp'd the orifice with the newly mention'd Cork so that the seal'd Bubble hanging at it was covered and every way surrounded by the oyl of Turpentine which being a liquor that at least in such Colds as we here have will not freez we plac'd the glass in beaten Ice and Salt and as it were buri'd it therein and at the end of about three
as our Author was descending into the golden Mine at Cremnitz he found in one place the heat to increase as he descended more and more which seems not to agree with a passage we lately mention'd out of him and to exceed any he had met with in any other Mine and afterwards the overseer bringing him into a room that abounded with smaragdine Vitriol the Mineral whence this heat proceeded though the room were spacious he found there besides a sharp spirit very offensive to his throat so troublesome a heat that he was ready to faint away with sweating and very much wondered how the diggers were able to work there And elsewhere the Author himself notes that such hot Mines of Vitriol or Sulphur may be found even in the first region of the earth as he calls that which is somewhat near the surface and which he thinks 〈◊〉 to name the cold region and within a large sphere of activity make it perpetually hot But this as I was intimating I mention but as a suspicion or a conjecture and notwithstanding that the degree of heat may be much increased in these Mines by the concurrance of accidental causes in case the conjecture be admitted yet since the frequency of a sensible degree of heat in very deep places does very little favour their opinion that will allow the earth to have no other heat but what it receives from the Sun beams or by the manifest fire of burning hills as Aetna and Vesuvius And if it should be objected that this Subterraneal heat is adventitious to the Earth which is supremely cold of its own nature Gassendus might reply that 't is as likely that the coldness of it near the superficies may be adventitious too and that it appears at least as manifestly that the one proceeds from the contiguous Air as it does that the other proceeds from some included fire and if I misremember not he hath this consideration that 't is somewhat strange that Nature should have intended the Earth for its summum frigidum and yet that a great part and for ought we know the greatest should be constantly kept warm either by the Sun as under the Torrid Zone or by the Subterraneal fires But the objection mention'd against Gassendus opposes but one of the Arguments we have alledg'd against the Earths being the primum frigidum and would leave the others in their force though it did more convincingly answer that against which 't is framed then it seems to do 10. And if the Patrons of the Earths coldness to evade the Arguments I have alledged should pretend that when they affirm the Earth to be the primum frigidum they mean not the Elementary Earth but some Body that is mingled with it I shall desire to know which 't is they mean of the many other Bodies that make up the Terrestrial Globe that we may examine what right it has to that Title and in the mean time I shall conclude against them that the Earth it self has none since they grant a colder Body then it and such a one as the earth must be beholding to for the greatest degrees of coldness it chances to possess 11. But though I presume enough has been said to make it appear unlikely that the Earth should be the primum frigidum yet I must in this dissent from the learned Gassendus that he thinks the Earth not only not to be the primum frigidum but not to be naturally cold any more then hot For the insensible parts of the Earth like those of other firm Bodies being heavy and perhaps gross and either having no constant motion at all or at least a far more remiss agitation then that of our Sensories it seems to follow that the Earth must seem cold to us unless it be by the communicated heat or motion of some extrinsick Agent put into a degree of agitation that belongs not to its nature and for the like reason I think it not improbable that pure Earth should in its own Nature be colder then either pure Water or pure Air since the Earth being a consistent Body its component particles are at rest among themselves or at least mov'd with an almost infinite slowness whereas Water and Air being fluids their component particles must be in a restless and various motion and consequently be less remote from heat which is a state wherein the various agitation of the minute particles is more vehement 12. And if those that plead for the Earth had declar'd that they meant not the pure or Elementary Earth but that part of the Terrestrial Globe that is distinct from the Sea and other Waters that make it up and would have Earth in that sense not to be the primum frigidum but only the summum frigidum perhaps they might have a better plea for their Opinion then they can urge for theirs who contend for the Water or the Air especially if to countenance their Opinion this memorable observation be added which I have met with among those Navigators that have had the greatest Experience of the Frigid Zone for the Dutch that sail'd thrice to Nova 〈◊〉 and once wintered there affirm in their first voyage that the highest degrees of Cold are not to be met with in the main Sea where yet men are most expos'd to the Operations of the Air and of the Water but either upon the Land or near it That accurate Geometrician and Hydrographer Fournier tells us that in 1595. the Hollanders being intercepted by Icy Scholes in the strait of Weigats and meeting with certain Muscovites demanded of them whether those Seas were always frozen and were answered that neither the Northern Sea nor that of Tartary did ever freez and that 't was only that strait with the Sea contiguous to the shores of some Bays and Gulphs that were frozen and our judicious Author not only adds that in effect all those that sail into those parts relate That all those Lumps of Ice are such as have been loosened and severed from the Islands and the Rivers of the Samojeds and Tartars but adventures to affirm in general terms that 't is certain the main Seas never freez and that 't is but the confines and shores of some of them that are frozen 13. That the water is the primum frigidum the Opinion of Aristotle has made it to be that of the schools and of the generality of Philosophers But I can as little acquiesce in this opinion as in the former not finding it agreeable to what experience teaches us 14. For not to mention that it would be very difficult to prove that divers very cold Bodies as Gold and Silver and Crystal and several other fusible stones have in them any water at all to which their coldness may with any degree of probability be ascribed nor to urge the Arguments that some Modern contenders for the supreme coldness of the Air are wont to imploy not I say to insist on such things
disapproved because it was likely and indeed we found it so by experience that the external air would first freez the uppermost part of the water contain'd in the stem and thereby hinder its ascent and perhaps occasion the bursting of the lower part of the said stem 8. Wherefore though for want of a sufficient Quantity of some liquor that would neither freez like water and aqueous Bodies nor congeal like common oyl and the like unctuous Juices we found it for a while somewhat difficult to practise the Experiment yet bethinking our selves of the indisposition that Brine has to Congelation we made so strong a Brine with common salt that with it and as I remember with oyl of Turpentine also of which we chanc'd to have some quantity by us we made divers Trials of which I had two among our Collections which we shall here subjoyn whereof the one informs us that an Egg being inverted into salt water the Cold of a frosty night made the air shrink in the Pipe near five inches and the other which is the accuratest I meet with among my Collections gives me this account That January the 29. the Air extended into 2057. spaces was by the cold of the sharp and frosty night contracted into 1965. spaces so that in extraordinarily cold weather the most we could make the Air lose of its former dimensions by the additional Cold of the Atmosphere was a 22. part and a little more then a third And this was the greatest condensation of the Air that we remember our selves to have observ'd though we were so careful as after we had placed marks where the incongealable liquor reach'd in the pipe that when the internal air was expos'd abroad to the cold we caused servants to watch and from time to time to take notice by placing marks of the various ascents of the liquor especially early in the morning least we should omit taking notice of the greatest contraction of the air which omission by reason that the Coldness of the ambient air does oftentimes begin to be remitted before we can feel it to be so is not easily avoided without watchfulness 9. But having thus observ'd the Condensation of included air by the natural and unassisted Cold of the external air we thought fit to prosecute the trial somewhat further and in regard we conceiv'd the Cold of a mixture of snow and salt to be far more intense then that of the mere ambient air alone we endeavoured to measure as near as we could how much the one exceeded the other And though we found that by prosecuting the lately mention'd Trial in the glass-Egg by the application of ice and salt to the Elliptical part of the vessel the liquor rise by our Estimate near four inches more then those five which it had risen already upon the account of the Refrigeration of the included air by the bare cold of the external Yet by prosecuting the other Experiment made the 29. of January at the same time when we were making it we did somewhat more accurately determine the matter For by applying ice and salt to the outside of the vessel we found that the included air was contracted from 1965. spaces to which the Cold of the ambient air had reduc'd it into 1860. spaces so that the Circumposition of ice and salt did as much nay somewhat more condense it after the mere Cold of the external air had contracted it as far as it could then the bare though intense Cold of the ambient air could condense it at first and the greatest degree of adventitious Cold we were able to give by the help of nature or of art did not make the air expos'd to it lose a full tenth part of its former Dimensions on which occasion it may not be unworthy observation That there is no greater Disparity betwixt the proportion in which the Cold was able to condense the Air and that wherein the Cold was able to expand water 10. This is all that at present I think fit to say concerning the interest that Winds may have in the Temperature of the Air. And therefore I will now proceed to those other particulars wherewith I not long since said that I intended to close up this Section and I might on this occasion subjoyn many things but partly haste and partly other considerations will confine me to those that relate to the effects of Cold upon the Air in a more general way 11. And first we will observe that Cold may hinder in an almost incredible measure the warming operation of the Sun upon the Air not only in the hottest part of the Day for that may sometimes happen even in our Climate but at several times of the Day even in the heat of Summer 12. I remember I once accidentally met with an intelligent and sober Gentleman who had several times sail'd upon the frigid Zone and though an intervening accident separated us so suddenly that I had not opportunity to obtain from him the resolution of above two or three questions yet this I learned of him belonging to our present purpose That by the help of a Journal he kept he call'd to mind that upon the coast of Greenland he had observ'd it to snow all Midsummer night which affirmation of so credible a person imboldens me to add some other relations which I should else have scrupled at 13. Mr. Logan an English Merchant that Winter'd at Pecora one of the Northern Towns of Muscovy relates that being there at a great Salmon-fishing there hapned about the close of August which in many Countries is wont to be the hottest time of all the year so strong a Frost which lasted till the fourth day That the Ozera was frozen over and the Ice driving in the River to and again broke all the Nets so that they got no Salmon no not so much as for their own Victuals 14. Captain G. Weymouth mentions that in July though he was not near the Latitude of Nova Zembla much less of Greenland yet sailing in a thick fog when by reason of the darkness it occasioned he thought good to take in some of his sails when his men came to hand them they found their Sails Ropes and Tacklings so hard frozen that it did says he seem very strange unto us being in the chiefest time of Summer 15. In the fifth Voyage of the English to Cherry Island which lies betwixt 74. and 75. degrees of Latitude they observ'd that the wind being at North-east upon the 24. of July It freez'd so hard that the Ice did hang on their 〈◊〉 And in the seventh Voyage which was made three years after to the same Island they mention that on the 14. of July the wind being Northerly they had both snow and frost 16. The next thing that we shall take notice of is the degree of Cold which the Efficient causes of that Quality whatever they be are able to produce in the air but of this
out of his Journal since they may at least help us to conjecture what is not to be expected in reference to Refractions from the coldness of the air as such The 21. of January says he I observed the 〈◊〉 〈◊〉 what exactness I could it being very clear Sunshine weather which I found to be 51. 52. This difference is by reason that here is a great Refraction Which last clause is very obscure unless it refers as one may guess it does to what he had elsewhere said That his first coming to the Island he took the Latitude with two Quadrants and found it to be inst 52. degrees without any minutes Elsewhere my 〈◊〉 says he by these glasses I compar'd to the Stars coming to the Meridian By this means we found the Sun to rise twenty minutes before it should and in the evening to remain above the horizon twenty minutes or thereabouts longer then it should And all this by reason of the Refraction And in another place March the 15. This evening says he the moon rose in a very long oval alongst the Horizon I shall add one passage more out of our Author concerning Refractions not only because it may bear Testimony to some relations of the like kind that I have mention'd in another Treatise but because it is concluded with an observation that if there be nothing of mistake in it is odd enough I had often says he observed the difference betwixt clear weather and misty Refractious weather in this manner From a little Hill which was near adjoyning to our house in the clearest weather when the Sun shone with all the purity of Air that I could conceive we could not see a little Istand which bare of us south south-east some four leagues of but if the weather were misty as aforesaid then we could often see it from the lowest place 23. Hitherto I have treated of the Temperature of the Air in general and though the past Discourse have been prolix enough yet possibly I may have no fewer things to say if I would at present fall upon the particular consideration of the three Regions into which the Air is wont to be distinguished For I confess I am not altogether without scruples both as to the Number and as to the Limits and as to the Qualities assign'd to these Aerial Regions But as I have partly declar'd in another Tract though I had time to enter upon so intricate a Disquisition yet till I have an opportunity to consult some other papers I know not whether what I have noted touching these difficulties may not more properly belong to another Treatise then this of Cold. 24. Having thus dispatch'd the few Experiments I can meet with among my papers concerning the Coldness of the Air I now proceed to subjoyn some observations that have occurr'd to me in the writings or verbal Relations of Navigators and Travellers about that subject But in regard that the greatest part of the Phaenomena of Cold which nature of her own accord presents us with seem to be produc'd either mediately or immediately by the Air we intend not here to treat of the coldness of the air in the largest sense but only to take notice of some of the choicer instances that seem to belong to our present Argument And these we shall annex either as Promiscuous Observations at the Close of this Section or as Illustrations or proofs of the three following Observations I. The first I shall propose in these terms that the greater or lesser coldness of the Air in several Climates and Countries is nothing near so regularly proportionate to their respective distances from the Pole or their vicinity to the Equator as men are wont to presume This puts me in mind of what I have formerly either heard from a skilful man or observ'd my self about the difference betwixt places of the same latitude in the Northern and Southern Hemisphere namely That of places equally distant the one from the Northern the other from the Southern Pole the latter are generally much colder then the former And as I remember I long since noted some things to this purpose but being not at present able to recover them I shall propose this only as that which may deserve an inquiry being not yet satisfi'd but that in the Examples I had taken notice of some accidental and concurrent causes may have occasion'd the greater coldness observ'd in the places seated on the other side of the Line as on this side of it the like causes may much vary the coldness of differing places of equal latitudes as we are now going to shew by the following testimonies 1. How excessive a Cold reigns at Musco and thereabouts in the Winter time when many men lose their noses or their toes and some their lives by the extremity of the cold we have several times occasion to take notice of in this Treatise And yet at Edenburgh which I find some of our modern Navigators to place more Northerly by above a degree there I say and in the neighbouring places the air is known to be temperate enough and the cold very tolerable And 't is affirm'd that the snow very rarely lyes any long time on the ground after it is fallen 2. In the Voyage made for discoveries northward by Mr. Poole in the year 1610. I find this passage I was certifi'd that all the Ponds and Lakes were unfrozen they being fresh water which putteth me in hope of a mild Summer here after so sharp a beginning as I have had and my opinion is such and I assure my self it is so that a passage may be as soon attain'd this way by the Pole as any unknown way whatsoever by reason the Sun doth give a great heat in this Climate and the Ice near the 79. degree I mean that that freezeth here is nothing so huge as I have seen in 73. degrees To this agrees the testimony of the Hollanders in their first Voyage to Nova Zembla in which the writer of it Gerat de Veer speaks thus We have assuredly found that the only and most hinderance to our Voyage was the Ice that we found about Nova Zembla under 73 74 75 and 76. degrees and not so much upon the Sea between both the lands whereby it appeareth that not the nearness of the North Pole but the Ice that cometh in and out from the Tartarian Sea about Nova Zembla caused 〈◊〉 to feel the greatest cold Therefore in regard that the nearness of the Pole was not the cause of the great cold that we felt c. And a little after It is true says he that in the Country lying under 80. degrees which we esteem to be Greenland there is both leaves and grass to be seen wherein such beasts as feed of leaves and grass as Harts Hinds and such like beasts live whereas to the contrary in Nova Zembla there groweth neither leaves nor grass and there are no beasts there
you shall see such a new hew and face of a Countrey the woods which for the most part are all of Fir and Birch so fresh and so sweet the Pastures and Meadows so green and well grown and that upon the sudden such variety of flowers such noise of Birds especially of Nightingals that seem to be more loud and of a more variable note then in other Countries that a man shall not lightly travel in a more pleasant Countrey And some lines after As the Winter exceedeth in cold so the Summer inclineth to 〈◊〉 much heat especially in the 〈◊〉 of June July and August being much warmer 〈◊〉 the Summer Air in England Almost like things have been much more recently affirm'd by the learned Olearius Secretary to the Duke of Holstein's Embassy into Russia and now Bibliothecarius to the present Prince of Holstein And an ac quaintance of mine who after having liv'd in Italy pass'd a Summer in Russia assur'd me that he scarce in Italy did ever eat better Melons then some which he had eaten at Musco of a strange bigness which bears witness to that almost incredible Relation of Olearius who after having much prais'd their goodness at Musco affirms that he there met with Melons of 40. pound weight of 〈◊〉 he there teaches the Culture At the royal City of China which scarce exceeding the 42. degrees of latitude one would expect that as the Summer is very warm so the Winter should be very mild as it is observ'd to be in divers places of Spain Italy and Greece that have the same or a more Northern latitude and yet the learned Jesuite Martinius who liv'd many years in China assures us that usually for four whole moneths together all the Rivers are so hard frozen that not only all Ships are clos'd and kept immovable by the Ice but that also horses wagons and even the heaviest carriages do securely pass over the Ice Concerning which he adds this strange circumstance that 't is usually made in one day though to its dissolution it require many Prosper Alpinus in his learned Treatise de medicina Aegyptiorum tells us that at Grand Cayro where he practis'd Physick though that famous Metropolis of Aegypt be distant but six degrees from the Tropick of Cancer yet the Air which in Summer is almost insupportably hot in Winter is sometimes very considerably cold adding that there is not any sort of Diseases that proceed as he is pleas'd to speak from distillations from the head to which the people are not there subject To these instances we shall annex but two more but those remarkable ones The first is mention'd by Purchase as communicated to him by an eye witness in these words This I thought good at our parting to advertise thee That Mr. Hebey hath affirm'd to me touching the diversity of weather in Greenland that one day it hath been so cold the wind blowing out of some quarter that they could scarce handle the frozen Sails another day so hot that the pitch melted of the Ship so that hardly they could keep their Clothes from pollution yea he hath seen at midnight Tobacco lighted or fired by the Sun beams with a glass The other example I am to produce is no less remarkable namely that in the often mention'd Charleton Island where that winter was as sharp perhaps as any known place of the habitable world Captain James his Journal gives us this account of the weather In June the sixteenth says he was wondrous hot with some thunder and lightning so that our men did go into the Ponds ashore to swim and cool themselves yet was the water very cold still Here had lately appeared divers sorts of Flies as Butterflies Butchers-flies Horse-flies and such an infinite abundance of blood-thirsty Muskitoes thatwewere more tormented with them then ever we were with the cold weather These I think lye dead in the old rotten wood all the Winter and in Summer they revive again Here be likewise infinite companies of Ants and Frogs in the Ponds upon the land Thus we see what difference there may be in the same place betwixt the temperature of the Air in Winter and Summer We shall now add what may appear more strange that there may be very great disparities in the heat and coldness of the air not only in the same place but within the compass of the same day The lately mention'd Alpinus affords me an example to this purpose in Aegypt its self where one would expect a much more uniform heat Hyeme says he nocturnus aer admodum frigidus observatur qui ob orto sole paulo post parum incalescit in meridieque plurimum adveniente vere nocte rursum infrigidum permutatur ita ut aer ille valdè inaequalis sit dicendus ab ipsiusque illa inaequalitate plurimi morbi originem ducunt atque generantur qui eo tempore per urbem vagantur The learned Olearius relating how he travelled with the Ambassadors whose Secretary he was over a branch of mount Taurus takes notice that it being after the middle of June the air of that hot region of Persia oblig'd them only to travel by night and yet the nocturnal cold was so great that they were all benummed with it insomuch that they were hardly able to alight from their Horses adding that the sudden change from an extreme cold to the excessive heat they were again expos'd to the next day cast no less then 15. of their company into strong burning feavers at once Which brought into my mind the complaint of good Jacob who though he liv'd in an Eastern Countrey when he had said that in the day the drought consumed him adds and the frost by night And the same curious traveller mentions that in another Countrey in Persia call'd Faclu notwithstanding the heat of the region at the end of March at which time they pass'd that way they saw and felt in one night which they were forc't to pass without their tents both lightning and thunders and winds and rain and snow and ice We will conclude with a remarkable instance afforded us by the Journal of the English that wintred at Charleton Island The season here in this Climate says the often quoted Author of the voyage is most unnatural for in the day time it will be extreme hot yea not indurable in the Sun which is by reason that it is a sandy Countrey In the night again it will freez an inch thick in the Ponds and in the Tubs about and in our house and all this towards the latter end of June III. The third observable I intended to take notice of about the Coldness of the Air may be compriz'd in this Proposition That in many places the Temperature of the Air as to Cold and Heat seems not to depend so much upon the Elevation of the Pole as upon the Nature and Circumstances of the winds that blow there It would require a very long Discourse
beget some Diffidence in wary men they would not be proper for the title of this Section and most of them that they may be fit to be plac'd here must be the Effects of such extreme degrees of Cold that I cannot in this temperate Climate of ours examine the truth of them by my own Trials so that all I can do is to make choice of such Relations as are almost all of them delivered by the Relators as upon their own Knowledge And even this may perchance not only gratifie and excite the Curiosity of some who are pleas'd with no things so much as with those that have somewhat in them of Prodigy and which is more considerable their Narratives may afford the Ingenious such strange Phaenomena that the Explication of them may serve both to exercise their wits and try their Hypothesis 2. It seems not necessary in the marshalling these observations to be scrupulous about method but yet to avoid confusion we shall first mention the Effects of Cold as to those four great Bodies of that part of the Sublunary World we live in that are commonly reputed Elements and thence we will proceed to take notice of the Effects of Cold upon some other inanimate Bodies and for an instance of its operation on living Creatures upon men 3. Of the power of Cold either to straiten the sphere of activity of fire or to hinder its wonted effects the chief examples I have met with are recorded partly by the Dutch in Nova Zembla and partly by Captain James when he winter'd in Charleton Island These Hollanders in one place speak thus The twentieth it was fair and still weather the wind Easterly then we wash'd our Sheets but it was so cold that when we had wash'd and wrung them they presently froze so stiff that although we laid them by a great fire the side that laid next the fire thaw'd but the other side was hard frozen c. Elsewhere thus We were in great fear that if the extremity of the Cold grew to be more and more we should all dye there with cold for what fire soever we made it would not warm us And because it were tedious to transcribe all that their Journals afford us to our present purpose we will conclude with this passage Hereby we were so fast shut up into the House as if we had been prisoners and it was so extreme Cold that the fire almost cast no heat for as we put our feet to the fire we burnt our hose before we could feel the heat so that we had work enough to do to patch our hose and which is more if we had not sooner smelt then felt them we should have burnt them ere we had known it Though Captain James wintred in a Countrey many degrees remoter from the Pole then Nova Zembla yet in one place he gives us this account of the colds power to restrain or oppose the action of fire The Cooks Tubs wherein he did water his meat standing about a yard from the fire and which he did all day ply with melted snow water yet in the night season while he slept but one watch would they be firm frozen to the very Bottom And therefore was he fain to water his meat in a Brass Kettle close adjoyning to the fire and I have many times both seen and felt by putting my hand into it that side which was next the fire was very warm and the other an inch frozen I leave the rest to our Cook who will almost speak miracles of the Cold. 3. Thus far our Enlish Navigator whose relation compar'd with those of the Hollanders make me not so much wonder as I once did that men should relate to Marcus Polus that there is a certain Plain in Tartary situated between some of the highest mountains in the World where if fire be kindled it is not so bright nor so effectual to boil any thing as in other places For so Purchase renders that passage whence occasion has been taken to impute to Marcus Polus a writer not always half so fabulous as many think him that he affirm'd that there was a Countrey in Tartary where fire could not be kindled 4. And as for the other newly mention'd relations of Seamen and Travellers though to us that live in England they cannot but seem very strange yet I am kept from rejecting them as utterly incredible by considering that ice and snow having before their Congelation been water must in probability owe their Coldness to that which reign'd in the Air So that if in any place Nature has either so plentifully stock'd the Air it self with frigorisick exspirations or other Corpuscles if we will admit any such or have upon any other account rendred it as cold as it can make ice and snow to be even here amongst us I know not why the Northerness of the climate and perhaps some saline expirations from the Earth and Sea may not there diffuse through the air a cold superior to that which by small Quantities of ice or snow and salt can at a small distance be produc'd here And this cold is so intense that by pouring some water on a Joynt-stool and placing on it a silver Tankard or other convenient vessel we may as experience has assur'd me with beaten ice or snow and salt and a little water which is added to hasten the solution of the other nimbly stirr'd together in the pot make the mixture freez the external water quite through the Tankard and they may be by this way so hard frozen together as that by lifting up the pot you may lift up the Joynt-stool too and that which is the circumstance for which I mention this just by the fire which in this case is unable to hinder so difficult an operation of the Cold. 5. Thus much of the effects of cold in reference to fire What the same quality may perform upon Air we shall say but little of in this place because we treat of those Phaenomena partly in the foregoing Section of the coldness of the Air and partly in other places Only we shall not here pretermit a testimony of the learned Olearius who as an eye witness confirms what we elsewhere deliver of the high degree of cold to which the Air may be brought For he tells us That in Muscovy he experimentally found that which others left recorded in their writings That ones spittle would be congeal'd before it reach'd the ground and that water would freez as it was dropping down 6. Of the effects of cold upon water we shall not need to say much in this place since the two notablest of them being the power cold has to congeal water suddenly and the force it has to turn vast quantities of it into sollid ice Of the former I have newly given out of Olearius an example as eminent as almost any that is to be met with and of the latter also I have given several instances in the Section
weight before they were so and kept in a pair of good Scales fasten'd to a frame in some quiet place well fenc'd from the Sun would by the cold of the Air in freezing weather be kept for any considerable time without a sensible diminution of weight but an unexpected thaw hindered us from seeing the success of what we design'd of this nature both as to Eggs and also some other Bodies For if the Experiment were very carefully tri'd upon a competent variety of them it might possibly assist us to guess especially in Camphire and some other easily exhalible bodies what interest Cold may have in suppressing or diminishing the expiration of their Effluvia 7. But to return to the weight of Bodies frozen and unfrozen we attempted to discover somewhat about it by several ways according as the differing accommodations we were furnish'd with permitted And of these trials I will mention four or five as well of the less as of the more accurate as my memory or Notes supply me with them 8. One of the less Accurate ways we imployed to try whether ice in which according to the Atomists great store of these frigorifick Corpuscles must be wedged would not upon their expulsion or recess leave the water lighter then was the ice was that which follows wherein to hasten the Experiment we mingled a little salt And though we foresaw there would be a difficulty from the Adhaesion of the vapors of the external Air to the outside of the glass we were to employ we thought that inconvenience might be remedied by well wiping off the frost or dew from the outside of the glass till it were clean and dry The event of the trial we find succinctly set down among our Notes as follows A single vial sealed up with ice and salt being wiped dry and weighed was found to weigh four ounces four drachms and a half when it was quite thawed it was found to weigh somewhat more then a grain less then its former counterpoise But more accurate and satisfactory Trials about this matter I find thus set down in one of my papers 9. We took a vial more thin then those that are commonly us'd that of the Aggregate of that and the Liquor the glass might make so much the lesser part This vial was furnished with a somewhat long neck which at the flame of a Lamp was drawn by degrees slenderer and slenderer that being very narrow at the Top it might the more readily and conveniently be seal'd notwithstanding the waters being in it then we almost fill'd it with that Liquor I say almost because a competent space ought to be left unfill'd to allow the water swell'd by glaciation room to expand it self This vial with the liquor in it was plac'd in a mixture of snow and salt after our usual manner and when the glass appear'd almost full of ice it was taken out and nimbly clos'd with Hermes's seal presently after this was weigh'd in a pair of very good Scales and the vial together with the contain'd liquor amounted to 〈◊〉 38. gr ss which yet was not all ice because these things could not be done so nimbly but that some of the ice began to thaw before we were able to dispatch them quite the vial thus seal'd being remov'd and suffered for two or three hours to thaw when the ice was vanish'd we weigh'd again the seal'd glass in the same Scales and found that it weigh'd as before at least if there were any difference it seem'd to weigh a little more But this Increment that amounted not quite to ½ a grain might easily be attributed to some difference in the weights and grains themselves wherein 't is not easie to find a perfect exactness or to some little unheeded moisture that might adhere to some part of the vial 10. And because it may be wished that as this Experiment shews the weight of Ice resolv'd into water to be the same with that of the solid ice so we had tri'd whether the weight of water congeal'd into ice would be the same with that of the former fluid water we will subjoyn what immediately follows in the same paper in these words 11. We took a seal'd vial very thin that it might be lighter but not so large as the other by about a third as amounting in the lately mention'd Scales but to 〈◊〉 〈◊〉 gr 41. when we had seal'd it up with the water in it This vial we plac'd as we had done the other in a mixture of snow and salt freezing it warily lest being seal'd it should break then we remov'd it into the same Scales to try whether it had got any weight by the suppos'd subingression of the Atoms of Cold which many learned men take to be the efficients of Congelation but it either weighed just as before or if there were any difference it seem'd to have lost ¼ of a grain Being suffer'd to thaw and put into the same Scales again it weigh'd just as much as it did when frozen though the weights were numerically the same and about ⅛ would sway the Scales or at least be sensible upon them But note that I was careful this last time to wipe the outside of the glass with a linen cloth because I have observ'd according to what I elsewhere deliver that in case ice be any thing hastily thaw'd it may produce a dew on the outside of the glass as I suspected that even the warm Air might in some measure do in this and if it had not been for this suspition some adhering dew that I was thereby enabled to detect and wipe off before I put the vial into the Scales might easily have impos'd upon us 12. These Trials I presume may give some satisfaction about the inquiry for the resolving whereof I thought fit to make them 13. But I was also desirous to see whether any difference as to weight would be produc'd by freezing and thawing if I may use those expressions in this case Iron Stone Wood or the like solid and permanent Bodies which I intended to have exactly weigh'd before and after their being expos'd to the Air and also after the frost was gone and all this against Counterpoizes not expos'd to so great a Cold would discover any sensible alteration as to weight that might safely be ascrib'd to the Cold. And though Avocations and the negligence of one that we imploy'd kept us from bringing the matter to such an issue as was desired yet the Trials seem'd not altogether irrational since we have formerly made it probable and have since met with fresh instances to confirm it that even Stones and Metals may resent some change of Texture by the operation of some degrees of Cold. And indeed induc'd by such considerations of that kind as seem'd the least doubtful I remember I sometime made several experiments of the weight of some metals and stones both before and after they had been much expos'd to a more vehement Cold then would
themselves again and fly about amazedly for a while but not long survive so great and sudden a change I have in another Treatise already said somewhat about this Tradition and therefore shall now say no more of it then these two things First that I since was assur'd by a person of honour that is very curious and was commanded by a many ways great Prince to inquire out the truth of it when he was in some of those Countries where the thing is said to be familiar enough and that the 〈◊〉 and soberest persons he could ask affirm'd the thing to be true But secondly having lately inquired about this matter of a knowing person of quality that was born and bred in Poland he answered me That in the parts where he liv'd it was a very general and unquestion'd opinion that Swallows often hid themselves all the Winter under water in Ponds and Lakes and Seggy places and that the Fishermen when having broken the ice they cast their Nets for Fish do draw them up benummed but not dead so that they quickly in Stoves recover their wings but seldom after that prolong their lives But as for their being taken up in ice he told me he had not heard of it though I see not why in case they commit themselves to shallow waters as those of Ponds and Seggy places often are a sharp lasting frost may not sometimes reach them And therefore that which left me the greatest scruple about this Tradition is That this Gentleman notwithstanding his curiosity could not affirm that ever he himself had seen any example of the thing he related But I will take this occasion to add that having a mind in frosty weather to try some Anatomical Experiments about Frogs one that I imploy'd breaking in a Ditch some ice that was very thick and of which he was to bring me a quantity found in the water that was under the ice good store of Frogs besides some Toads which I found to be very lively and divers of which I kept for certain uses a good while after To confirm and to add some Paralipomena unto what I have deliver'd in the Second and in the Twentieth Titles about the frosts getting into hard and solid bodies I shall here subjoyn some particulars there omitted which I have learned partly from Experiments and partly from persons worthy of credit whom I purposely consulted about this matter And first as to the freezing of Wood we have sometimes tri'd it by purposely exposing partly other Wood and partly branches cut off from growing Trees to an intense degree of Cold by which the wood seem'd in one night to be for some little depth manifestly enough invaded by the frost But a domestick of mine having a little while since had occasion to fell an old Apple-tree on a day that had been preceded by a fortnights bitter frost came and informed me That he found that the frost had evidently pierc'd into the very middle of it though it were about a foot in Diameter And an Experienc'd Artificer whose head and hand were much imploy'd about the building of great mens houses told me that he had often seen here in England pieces of Timber it self manifestly frozen and rendred exceeding difficult to be saw'd the frost also appearing by evident signs to continue in the saw-dust And therefore it will be the less strange if in Poland the effects of Cold upon wood be more conspicuous For a learned native assur'd me that in his Countrey 't was usual to have wood frozen so hard that the Hatchets would not cut it but rebound from it and that 't was very usual to hear in the night a great many loud cracks almost like the reports of Pistols of the shingles or wooden tyles wherewith in many places they cover their houses instead of Slate and this as I purposely ask'd when the weather was dry and excessively cold When I likewise inquir'd about the thawing of wood he told me he had several times seen pieces of Timber which having been throughly frozen in the Air did when brought into rooms made warm by Stoves become cover'd with a kind of hoar frost and made them look white and that though his Bow which he shew'd me were very strong and tough as being made not of wood but horn and other close materials it would be so chang'd by the frost that unless special care were had in the thawing of it it would break That Marle and Chalk and other less solid terrestrial Concretions will be shatter'd by strong and durable frosts is observ'd by Husbandmen who thereby find it the better fitted to manure their land the Texture of those bodies during whose intireness the parts most proper to feed grass and corn are more lock'd up being by congelation in great part dissolv'd but that true and solid stones wont to be imploy'd in noble and durable Buildings should be spoil'd by the frost will perhaps to most readers seem very improbable And therefore I shall here add what I have learn'd by inquiry of the ingeniousest and most experienc'd Mason I have met with because it may not only surprize most readers but prove an useful observation to him Having then inquir'd of this Tradesman whether he did not find that some free stone a name vulgarly known would not be spoil'd by the frost he told me that he had often observ'd both free stone and harder stones then that to be exceedingly spoil'd by the frost and reduc'd to crack or scale off to the blemishing and prejudice of the houses that are built of them But because it may be objected against this that experience shews us that divers of the stateliest Fabricks in England have these stones for their chief materials and yet indure very well the inclemencies of the Air the reply may be that the difference may not consist in the peculiar natures of the stones imploy'd but in the several seasons in which the same kind of stones are digg'd out of the Quarry For if they be digg'd up when the cold weather is already come in and imploy'd in building the same Winter they will upon very hard frosts be apt to be shatter'd or scale but if they be digg'd early in the Summer and suffer'd to lye expos'd to the Sun and Air during all the heat of the Summer these season'd stones if I may so call them may outlast many sharp Winters unimpair'd It seems to me worth trying whether during their insolation if that term may be allow'd me there do not by the operation of the heat and air upon them exhale a certain unripe mineral sap or moisture whose recess may perhaps be discover'd by weight which if it remain in the stone may by very piercing frosts be congeal'd almost like the sap in Timber-trees and shatter the Texture of the stone which agrees well with what was told me by an understanding person that is Master of a great Glass-house of whom having purposely inquir'd whether he did
taken notice of were able to vary their success In confirmation of what is delivered in the VII Section about the expansion of water by freezing I shall add that having caus'd some strong glass-Bottles of a not inconsiderable bignéss to be fill'd with a congealable liquor excepting the necks which were fill'd with Sallet oyl I observ'd that in a somewhat long and very sharp frost the contained water was so far expanded by congelation that it not only thrust up the corks but the cold having taken away the defluency of the oyl that liquor together with the water that could no longer be contain'd in the Cavities of the glasses being as it seem'd frozen as fast as it was thrust out of the neck there appear'd quite above the upper part of the Bottles Cylinders of divers inches in height consisting partly of concreted oyl and partly of congeal'd water having on their tops the corks that had been rais'd by them It is a Tradition very currant among us that when Ponds or Rivers are frozen over unless the ice be seasonably broken in several places the Fishes will dye for want of Air. And I find this Tradition to be more general then before I made particular inquiry into it I knew of For Olaus Magnus mentions it more then once without at all questioning the truth of it but rather as if the general practise of the Northern Nations to break in divers places their frozen Ponds and Rivers were grounded upon the certainty of it In the twentieth Book which treats of Fishes after having spoke of the reasons why the Northern Fishermen imploy so much pains and industry to fish under the ice and having said among other things that the nature of the Fish exacts it he adds this reason that Nisi glacie perforata respiracula susciperent quotquot in flumine vel stagno versantur subito morerentur Another passage of the same Author and taken likewise out of the same 20. Book you may meet with in the Margent though in another place he seems to intimate another and not an absurd reason of the death of Fishes in Winter where advertising the Reader that Ponds and Lakes did generally begin to freez in October he adds that Fishes are usually found suffocated when the Thaw comes where veins or springs of living water do not enter by which passage he seems to make the want of shifted water cooperate to the suffocation of the Fishes And to the same purpose I shall now add that having inquir'd of a learned Native that had had about Cracovia whose Territory is said to abound much in Ponds whether the Polanders also us'd the same custome he answered me that they did and that sometimes in larger Ponds they were careful to break the ice in eight or ten several places to make so many either vents or Air-holes for the preservation as they suppos'd of the Fish And when I inquir'd of the often mention'd Russian Emperors Physician whether in Muscovy the frost kill'd the Fishes in the Ponds in case the ice were not broken to give them Air he answered that in ordinary Ponds it were not to be doubted but that in great Lakes he could not tell because the Fishermen use to break many great holes in the ice for the taking of the Fish For at each of these holes they thrust in a Net and all these Nets are drawn up together in one great breach made insome convenient place near the middle of the rest It appears then that the Tradition is general enough but whether it be well grounded I dare not determine either affirmatively or negatively till trial have been made in Ponds with more of design or of curiosity and watchfulness then I have known hitherto done men seeming to have acquiesc'd in the Tradition without examining it and to have been more careful not to omit what is generally believ'd necessary to the preservation of their Fish then to try whether they would escape without it Wherefore though for ought I know the Tradition may prove true yet to induce men not to think it certain till experience has duly convinc'd them of it I shall represent That as much as I have in other Treatises manifested how necessary Air is to Animals yet whether Fishes may not live either without Air or without any more of it then they may find interspers'd in the water they swim in has not yet that I know of been sufficiently prov'd For what we have attempted of that nature in our Pneumatical Engine whether it be satisfactory or not is not yet divulged And I remember not to have hitherto met with any writer except Olaus be construed to intimate so much that affirms upon his own observation that the want of breaking ice in Ponds has destroy'd all the Fish Besides that possibly in frozen Ponds there may be other reasons of the death of the Fishes that are kill'd if any store of them be so by very sharp frosts For who knows what the locking up of some kinds of subterraneal steams that are wont freely to ascend through water unfrozen may do to vitiate and infect the unventulated water and make it noxious to the Fishes that live in it perhaps also the excrementitious steams that insensibly issue out of the bodies of the Fishes themselves may by being penn'd up by the ice contribute in some cases to the vitiating of the water at least in reference to some sort of Fishes For being desirous to learn from a person curious of the ways of preserving and transporting Fish whether some Fishes would not quickly languish grow sick and sometimes dy out-right if the water they swam in were not often shifted he assur'd me that some kinds of them would and it has not yet that I hear of been tri'd whether or no though Ponds seldom freez to the bottom yet the water that remains under the ice in which it self some Fishes may be now and then intercepted may not even whilest it continues uncongeal'd admit a degree of cold that though not great enough to turn water into ice may yet be great enough when it continues very long to destroy Fishes though not immediately yet within a less space of time then that during which the surface of the Pond continues frozen But 't is not worth while to be sollicitous about conjectures of causes till we are sure of the Truth of the Phaenomenon and these things are propos'd not so much to confute the Tradition we have been speaking of as to bring it to a Trial which having no opportunity to make in Ponds I endeavour'd as well this Winter as formerly to obtain what information I could from Trials made in small vessels with the few Fishes I was able to procure And I shall subjoyn most of these Trials not because I think them very considerable but because they are for ought I know the only attempts of the kind that have yet been made To satisfie my self whether the ices denying
18. Title where I recited the Experiment of the infrigidating Winds I should more expresly have taken notice of this circumstance that to satisfie my self that 't was not the bare Wind as such whose operation upon the Air included in the Ball of a Weather-glass made the liquor to ascend we put a mark upon the height it stood at when we had a pretty while blown upon it and then without removing the Bellows put ice and salt about the Iron pipe of it By which mixture the Air that was afterwards blown through that pipe was so cool'd in its passage as to make the liquor very manifestly to ascend even in a Weather-glass where I did imploy as I have elsewhere declared that I often do Quicksilver instead of water or spirit of Wine And least the vicinity of the frigorifick mixture should be suspected to have caus'd this contraction of the included Air we did sometimes purposely intermit the moving of the Bellows without removing the Weather-glass and though notwithstanding that vicinity the liquor would begin a little to subside yet when ever the cold spirits or the Corpuscles of the highly refrigerated Air were by the playing of the Bellows anew approach'd to or rather brought to touch in swarms the globular part of the instrument the Mercury would manifestly ascend And since we are speaking of Weather-glasses I shall on this occasion subjoyn That certain circumstances may also vary the success of another Experiment somewhat of kin to that lately repeated about the pendulous Drop which is briefly mentioned not far from the beginning of the first Praeliminary Discourse For though the common Thermometers that are here wont to be sold in shops have usually the Pipe of the Bolthead very large in proportion to the Ball and therefore are in that place said to be Weather-glasses not nice and though on such instruments in certain Temperatures of the Air intimated by the word sometimes imploy'd in that passage the Air blown out of a pair of Bellows against some part of the included Air would not especially at the beginning make the Air sensibly contract it self and the liquor ascend though at the very first and second blast the coldness of this artificial Wind might be very sensible to the touch which was the thing intended to be taught in that passage yet having the curiosity with other Bellows at another season of the year to blow long upon the Ball of a not common but nice Weather-glass of my own making furnished with a pipe that was very slender I divers times but not always found the tincted liquor manifestly enough to ascend as if the Wind consisting of a more compress'd Air did by containing a greater number of cold particles in the same room more affect the internal Air then the contact of the calm and lax outward Air did before which disparity of events has given me the design of making further Trials with differing Thermoscopes at other seasons of the year to see if I can bring the matter to some certainty by discovering the cause of this contingency in which I afterwards suspected that some light degree of warmth or coolness in the Bellows themselves which as being unmanifest to the sense scap'd unheeded might have an interest When I was about some of the former Experiments I would willingly have had an opportunity of trying with a good seal'd Weather-glass what difference there would be betwixt the cold of the nocturnal Air in a frosty night in places where the Air was kept calm by being shelter'd from the wind not by inhabited buildings but by some Wall or other body whence any warm Effluviums were least to be expected and betwixt the cold of the same Air in places where cold winds especially Northerly or Easterly did freely and strongly blow But my occasions then confining me to a Town I had not conveniency to make any secure observations of that nature and even in a more commodious place unless it were determined whether there be Corpuscles properly and constantly frigorifick upon whose account some winds are so much colder then others there may arise more scruples about this matter then I must now stay to discuss There is one thing more that it may be is not impertinent to mention before I take leave of the XVIII Title for in confirmation of what is there delivered concerning the Vicissitudes of these troublesome degrees of cold and heat within the the compass of the same Natural day complain'd of by the Patriarch Jacob and by Olearius I shall add that having since had opportunity to inquire about such matters of a learned Physician lately come from the Indies he assur'd me that notwithstanding the violent heats of the day he usually observed the nights to be so very cold that he was perswaded some positively frigorifick steams did in the night ascend out of the Earth and make it very expedient if not necessary for those English that live in the warmer parts of America to imitate the Natives in keeping fires under their Hammacks or hanging Beds I thought it might be a Luciferous Experiment in relation to an Hypothesis that might be propos'd about cold to try whether if two such liquors were provided as by being mix'd together would so far forth lose their fluidity as to obtain at least the consistence of an Unguent this impediment put to the former confused and greater agitation of their parts would produce any sensible degree of cold this I thought fit to try by immersing for a competent time the Ball of a tender seal'd Weather-glass into each of the liquors apart and then into the soft mixture their coalition would compose To produce such a mixture more ways then one it was not difficult for me by the help of some Experiments I had provided to add to my History of fluidity and sirmness But though a strong solution of Minium or calcined Lead in spirit of Vineger or a very strong infusion of good quick-Lime in water will either of them and one of them I did make use of though I have forgotten which coagulate a just proportion of good Sallet Oyl to name no other made by expression into such a consistence as I have been speaking of yet for want of a seal'd Thermoscope tender enough I cannot now repeat the Experiment and till I do I dare not draw any conclusion from it though if I much misremember not when I show'd it an ingenious person neither he nor I could perceive that the liquors by being depriv'd of their fluidity had acquir'd any thing of coldness discoverable by the seal'd Weather-glass It is much controverted among the Curious whether water be capable of Compression and divers have of late inclin'd to the negative upon observing a want of cogency in the Experiments that have been brought to evince the affirmative What Trials and Observations we long since made about this matter may be met with in some of our other Treatises wherefore I shall now subjoyn that