much of the water consisting perhaps of Corpuscles more pliant to the internal surfaces of the glass was contiguous to the sides it was shown that in case the little Glass-Vessel that held the water of which a part ascended into the slender Pipe were so closed that a man might with his mouth suck the Air out of it the water would immediatly subside in the small Pipe And this would indeed infer that it asscended before only by the pressure of the incumbent Air. But that it may how justly I know not be objected that peradventure this would not happen in case the upper end of the Pipe were in a vacuum And that 't is very probable the water may subside not because the pressure of the internal Air is taken off by exsuction but by reason of the spring of the external Air which impels the water it finds in its way to the Cavity deserted by the other Air and would as well impel the same water upwards as make it subside if it were not for the accidental posture of the Glasses However having not now leisure to examine any further this Matter I shall only mind your Lordship that if You will prosecute this Speculation it will be pertinent to find out likewise Why the surface of Water as is manifest in Pipes uses to be concave being depressed in the middle and higher on every side and why in Quick-silver on the contrary not only the surface is wont to be very convex or swelling in the middle but if you dip the end of a slender Pipe in it the surface of the Liquor as 't is called will be lower within the Pipe than without Which Phaenomena whither and how far they may be deduced from the Figure of the Mercurial Corpuscles and the Shape of the Springy Particles of the Air I willingly leave to be considered An Attempt for the Explication of this New Experiment MY former Conjecture That the unequal height of the surfaces of the water proceeded from the greater pressure made upon the water by the Air without the Pipes A. B. C. than by that within them I shall endeavour to confirm from the Truth of the two following Propositions The first of which is That an unequal pressure of the incumbent Air will cause an unequal height in the waters Surfaces And the Second is That in this Experiment there is such an unequal pressure Now that the First is true the following Experiment will evince For if you take any Vessel so contrived as that you can at pleasure either increase or diminish the pressure of the Air upon this or that part of the Superficies of the water the equality of the height of those parts will presently be lost And that part of the Superficies that sustains the greater pressure will be inferiour to that which undergoes the less A fit Vessel for this purpose will be an inverted Glass Syphon such an one as is described in the Sixth Figure For if into it you put a quantity of Water suppose enough to fill it as high as the Line A. B. and applying your mouth to one end as to D. you shall find that by gently blowing in at it you shall depress the Superficies B. and thereby raise the opposite Superficies A. to a considerable distance and by gently sucking you may perceive the clean contrary effects produced Next That there is such an unequal pressure I shall prove from this that there is a much greater inconformity or incongruity call it what you please of Air to Glass and some other Bodies than there is of Water to the same What I mean hereby I shall in short explain by defining conformity or congruity to be a property of a fluid Body whereby any part of it is readily united or intermingled with any other part either of it self or of any other Homogeneal or Similar fluid or firm and solid body And unconformity or incongruity to be a property of a fluid by which it is kept off and hindred from uniting or mingling with any heterogeneous or dissimilar fluid or solid Body This last property any one that hath been observingly conversant about fluid Bodies cannot be ignorant of For not now to mention several Chimical Spirits and Oyles which will very hardly if at all be brought to mix with one another insomuch that there may be found some 8 or 9 or more several distinct Liquors which swimming one upon another will not be brought to mix we need seek no further for Examples of this kind than to observe the drops of rain falling through the air and the Bubbles of air which are by any means conveyed under the surface of the Water or a drop of common Sallet Oyl swimming upon water In all which and many more Examples that might be enumerated of this sort the incongruity of two fluids is easily discernable And as for examples of Congruity or Incongruity of Liquids one with another or with several kinds of firm or solid Bodies they have long since been taken notice of and called by the Names of Drieness and Moysture though these two Names are not comprehensive enough they being commonly used to signifie only the adhering or not adhering of water to some other solid Bodies of this kind we may observe that water will more readily wet some woods than others and that water let fall upon a Feather the whiter side of a Colwort and some other leaves or upon almost any unctuous or resinous superficies c. will not at all adhere to them but easily tumble off from them like a solid Bowl whereas if dropt upon Linnen Paper Clay green Wood c. it will not be taken off without leaving some part of it behind adhering to them So Quicksilver which will very hardly be brought to stick to any vegetable body will readily adhere to and mingle with several clean metalline bodies Now from what cause this congruity or Incongruity of bodies one to another does proceed whether from the Figure of their constituent Particles or interspersed pores or from the differing motions of the parts of the one and the other as whether circular undulating progressive c. whether I say from one or more or none of these enumerated causes I shall not here determine It being an enquiry more proper to be followed and explained among the general Principles of Philosophy whither at present I shall refer it as fearing lest it might here seem absurd without the concatenation of several other Principles to explicate it and knowing it likewise sufficient for this enquiry to shew that there is such a property from what cause soever it proceeds These Properties therefore alwaies the concomitants of fluid bodies produce these following visible Effects First They unite the parts of a fluid to its homogeneal Solid or keep them separate from its heterogeneal Hence Quicksilver will as we noted before stick to Gold Silver Tin Lead c. and unite with them but roule off from wood stone glass
if never so little scituated out of its horizontale Paralelisme and water that will wet salt and dissolve it will slip off from Tallow or the like without at all adhering as it may likewise be observed to do upon a dusty superficies And next they cause the parts of homogeneal fluid bodies readily to adhere together and mix and of heterogeneal to be exceeding averse thereunto Hence we find that two small drops of water on any superficies they can roule on will if they chance to touch each other readily unite and mix in one 3d. Globule or drop the like may be observed with two small Bowls of Quicksilver upon a Table or Glass provided the surfaces of those Globule be not dusty and with two drops of Oyl upon fair water c. And further water put unto wine salt water Vinegar spirit of wine or the like does immediatly especially if they be shaken together disperse it self all over them hence on the contrary also we find that water powred upon Quicksilver and Oyl upon that water and Air upon that Oyl though they be stopt closely up into a Bottle and shaken never so much they will by no means long suffer any of their bigger parts to be united or included within any of the other Liquors by which recited Liquors may be plainly enough represented the 4 Peripaterical Elements From this property 't is that a drop of water does not mingle with or vanish into Air but is driven by that fluid equality protruding it on every side and forc't into as little a space as it can possibly be contained in namely into a Round Globule So likewise a little air blown under the water is united or thrust into a Bubble by the ambient water And a parcel of Quicksilver enclosed with Air water or almost any other liquor is formed into a round Ball. Now the cause why all these included fluids newly mentioned or as many others as are wholly included within a heterogeneous fluid are not exactly of a spherical Figure seeing that if caused by these Principles only it could be of no other must proceed from some other kind of pressure against the two opposite flatted sides This adventitious or accidental pressure may proceed from divers causes and accordingly must diversifie the Figure of the included heterogeneous fluid For seeing that a body may be included either with a fluid only or only with a solid or partly with a fluid and partly with a solid or partly with one fluid and partly with another there will be found a very great variety of the terminating surfaces much differing from a Spherical according to the various resistance or pressure that belongs to each of these encompassing mediums Which Properties may in general be deduced from two heads viz. Motion and Rest. For either this Globular Figure is altered by a natural Motion such as is Gravity or a violent such as iâ— any accidental motion of the fluids as we see in the wind rufling up the water and the purlings of Streams and foaming of Cartaracts and the like which because they are so obvious and easily understood and so little pertinent to our present enquiry I shall refer to some other intended Speculations to which they do more properly belong Or thirdly By the Firmness and Stability of the ambient Solid For if the including Solid be of an angular or any other irregular Form the included fluid will be near of the like as a Pint Pot full of water or a Bladder full of Air. And next if the including or included fluid have a greater gravity one than another then will the globular Form be deprest into an Eliptico-spherical As if for example we suppose the Circle A. B. C. D. in the first Figure to represent a drop of water Quick-silver or the like included with the Air or the like which supposing there were no gravity at all in either of the fluids or that the contained and containing were of the same weight would be equally deprest into an exactly-spherical body the ambient pressing equally against every side of it But supposing either a greater gravity in the included by reason whereof the parts of it being prest from A. towards B. and thereby the whole put into motion and that motion being hindred by the resistance of the subjacent parts of the ambient the globular Figure A. D. B. C. will be deprest into the Eliptico-spherical E. G. F. H. For the side A. is detruded to E. by the Gravity and B. to F. by the resistance of the subjacent medium and therefore C. must necessarily be thrust to G. and D. to H. Or else supposing a greater gravity in the ambient by whose more than ordinary pressure against the under side of the included globul B. will be forced to F. by its resistance of the motion upwards the side A. will be deprest to E. and therefore C. being thrust to G. D. to H. the globular Figure by this means also will be made an Eliptico-spherical Next if a fluid be included partly with one and partly with another fluid it will be found to be shaped diversly according to the proportion of the gravity and incongruity of the 3 fluids one to another as in the second Figure let the upper M M M be Air the middle L. M. N. O be common Oyle the lower O. O. O. be water the Oyl will be form'd not into a spherical Figure such as is represented by the pricked Line but into such a Figure as L. M. N. O. whose side L. M. N. will be of a flatter Eliptical Figure by reason of the great disproportion between the Gravity of Oyle and Air and the side L. O. M. of a rounder because of the smaller difference between the weight of Oyle and water Lastly The globular Figure will be changed if the ambient be partly fluid and partly solid And here the termination of the incompassed fluid towards the incompassing is shap'd according to the proportion of the congruity or incongruity of the fluids to the solids and of the gravity and incongruity of the fluids one to another As suppose the subjacent medium that hinders an included fluid's descent be a solid as let K. L. in the first Figure represent the smooth superficies of a Table E. G. F. H. a parcel of running Mercury the side G. F. H. will be more flatted according to the proportion of the incongruity of the Mercury and Air to the Wood and of the gravity of Mercury and Air one to another The side G. E. H. will likewise be a little more deprest by reason the subjacent parts are now at rest which were before in motion I have not here time nor is it much to my present purpose to shew how much the Figure of the descending fluid may be altered from this Eliptico spherical Figure by a very small resistance of the subjacent medium for the advantage the under parts of the descendent may have as to the
to pass may contain a salt that mixing and uniting with the Sea salt may precipitate it much after the same manner as the Alkalizate and Acid Salts mix and precipitate each other in the preparation of Tartarum Vitriolatum I know not also whether the exceeding cold that must necessarily be at the bottom of the water may not help towards this separation for we find that warm water is able to dissolve and contain more salt than the same cold insomuch that Brines strongly impregnated by heat if let cool do suffer much of their salt to subside and chrystallize about the bottom and sides I know not also whether the exceeding pressure of the parts of the water one against another may not keep the Salt from descending to the very bottom as finding little or no room to insert it self between those parts protruded so violently together or else squeeze it upwards into the superiour parts of the Sea where it may more easily obtain room for it self amongst the parts of the water by reason that there is more heat and less pressure To this Opinion I was somwhat the more induced by the relations I have met with in several Geographical Writers of drawing fresh water from the bottom of the Sea which is salt above I cannot now stand to examine whether this natural perpetual motion may not artificially be imitated Nor can I stand to answer the Objections which may be made against this my Supposition As First How it comes to pass that there are somtimes salt Springs much higher than the Superficies of the water And Secondly Why Springs do not run faster and flower according to the varying height made of the Cylinder of Sea-water by the ebbing and flowing of the Sea As to the First In short I say the fresh water may receive again a saline Tincture near the Superficies of the Earth by passing through some salt Mines or else many of the saline parts of the Sea may be kept back though not all And as to the Second The same Spring may be fed and supply'd by divers Caverns coming from very far distant parts of the Sea so as that it may in one place be high in another low water and so by that means the Spring may be equally supply'd at all times Or else the Cavern may be so straight and narrow that the water not having so ready and free passage through it cannot upon so short and quick mutations of pressure be able to produce any sensible effect at such a distance Besides that to confirm this hypothesis there are many Examples found in Natural Historians of Springs that do ebb and flow like the Sea As particularly those recorded by the Learned Camden and after him by Speed to be found in this Island One of which they relate to be on the Top of a Mountain by the small Village Kilken in Flintshire Maris aemulus qui statis temporibus suas revomit resorbet Aquas which at certain times riseth and falleth after the manner of Sea-Tides A Second in Caermardenshire near Caermarden at a place call'd Cantred Bichan Qui ut scribit Giraldus naturali die bis undis deficiens toties exuberans marinas imitatur instabilitates That twice in four and twenty hours ebbing and flowing resembleth the uustable Motions of the Sea The Phanomena of which two may be easily made out by supposing their Cavern by which they are fed to arise from the bottom of the next Sea A Third is a Well upon the River Ogmore in Glamorganshire and near unto Newton of which Camhden relates himself to be certified by a Letter from a Learned Friend of his that observed it Fons abest hinc c. The Letter is a little too long to be inserted but the substance is this that this Well ebbs and flows quite contrarily to the flowing and ebbing of the Sea in those parts for 't is almost empty at Full Sea but full at Low water This may happen from the Channel by which it is supplied which may come from the bottom of a Sea very remote from those parts and where the Tides are much differing from those of the approximate shores A Fourth lies in Westmerland near the River Loder Qui instar Euripi saepius in die reciprocantibus undis fluit refluit which ebbs and flows many times a day This may proceed from its being supply'd from many Channels coming from several parts of the Sea lying sufficiently distant asunder to have the times of High-Water differing enough one from the other so as that whensoever it shall be High Water over any of those places where these Channels begin it shall likewise be so in the Well But this is but a Supposition A Seventh thing was Whether in general the Glutinousness of most bodies may not be partly attributed to this property For supposing glutinous bodies to be such as will easily conform themselves to the superficies of homogeneal bodies and being suffered for some time to rest in that Position until they grow hard the intercourse of the Air or other fluid body being hindred the force requisite to disjoyn those two superficies must necessarily be such as is able to preponderate and prevail against the pressure of the Air upon a superficies equal to that of the body which is toucht by the glutinous substance for these two touch so exactly that 't is impossible for the Air to get between until they are somwhat disjoyn'd by which means the pressure of the Air can only be against the two outward sides opposite to those which joyn them together This may be confirmed by the Experiment of two flat Marbles pieces of Glass and the like smooth bodies for if they be so exactly plain that by rubbing them together you can detrude the interjacent Air you shall find them stick so hard that an ordinary strength can hardly separate them especially if they be of any bigness This Property I say may at least be the cause why some bodies adhere to Glass and the like For I am not ignorant that as for Wood and many other porous bodies the glutinous substance may penetrate into their little cavities and so hardning become little Hooks or Buttons that may contribute much to the former Cohesion An Eighth Query was Whether the dissolution or mixing of several bodies whether fluid or solid with saline or other Liquors might not partly be attributed to this Principle of the congruity of those bodies and their dissolvents As of Salt in water Metals in several Menstruums Unctuous Gums in Oyles the Mixing of Wine and water c. And whether precipitation be not partly made from the same Principle of Incongruity I say partly because there are in some dissolutions some other Causes concurrent I shall lastly make a much more seemingly strange and unlikely Query and that is Whether this Principle well examined and explain'd may not be found a co-efficient in the most considerable Operations of Nature As in
those of Heat and Light and consequently of Rarefaction and Condensation Hardness or Solidity and Fluidness Perspicuity and Opacousness Refractions and Colours c. Nay I know not whether there may be many things done in Nature in which this may not be said to have a Finger This I may possibly further enquire into and examine if God grant me Life and Opportunity In the mean time I would not be thought guilty of that Errour which the thrice Noble and Learned Verulam justly takes notice of as such and cals Philosophiae Genus Empiricum quod in paucorum Experimentorum Angustiis Obscuritate fundatum est For I neither conclude from one single Experiment nor are the Experiments I make use of all made upon one Subject Nor wrest I any Experiment to make it quadrare with any preconceiv'd Notion But on the contrary I endeavour to be conversant in all kind of Experiments and all and every one of those Trials I make the standards as I may say or Touchstones by which I try all my former Notions whether they hold not in weight and measure and touch c. For as that Body is no other than a Counterfeit Gold which wants any one of the Proprieties of Gold such as are the Malleableness Weight Colour Fixtness in the Fire Indissolubleness in Aqua-fortis and the like though it has all the other so will all those notions be found to be false and deceitful that will not undergo all the Trials and Tests made of them by Experiments And therefore such as will not come up to the desired Apex of Perfection I rather wholly reject and take a new than by piecing and patching endeavour to retain the old as knowing old things to be rather made worse by mending than better And this course I learn'd from Nature whom we find neglectful of the old Body and suffering its Decaies and Infirmities to remain without repair and altogether sollicitous and careful of perpetuating the Species by new Individuals And 't is certainly the most likely way to erect a glorious and everlasting structure and Temple to Nature such as she will be found by any zealous Votary to reside in first to raze the old Pile built upon unstable Fancies and unsound opinions and to begin a new upon a sure Foundation of Experiments Thus Medaea when she renewed old Aeson first searches Heaven and Earth gathers and collects simples and Ingredients of all kinds nor would these do any thing till well mixt concocted and digested Omnia confudit summisque immiscuit ima Then we find her examine whether it will do what she expected Ecce vetus calido versatus stipes aheno Fit viridis primo nec longo tempore frondes Induit subito gravidis oneratur Olivis At quacunque cavo spumas ejecit aheno Ignis in terram guttas cecidere calentes Vernat humus floresque mollia pabula surgunt And finding it to come up to what she desired she then begins her great work Quae simul ac vidit stricto Medaea recludit Ense senis jugulum veteremque exire cruorem Passa replet succis After which what succeeded but a miraculous Renovation Barba comaeque Canitie posita nigrum rapuere colorem Pulsa fugit macies Abeunt pallorque situsque Adjectoque cavae supplentur corpore rugae Membraque luxuriant The Application of it is obvious and therefore to digress no further from the consideration of the Phaenomena more immediatly explicable by this Experiment we shall proceed to shew That As to the rising of water in a Filtre the reason of it will be manifest to him that does take notice that a Filtre is constituted of a great number of small long solid bodies which lie so close together that the Air in its getting in between them doth lose of its pressure that it has against the fluid without them by which means the water or liquor not finding so strong a resistance between them as is able to counter ballance the pressure on its superficies without is raised upwaâ—d till it meet with a pressure of the Air which is able to hinder it And as to the Rising of Oyl melted Tallow Spirit of Wine c. in the Weeck of a Candle or Lamp it is evident that it differs in nothing from the former save only in this that in a Filtre the Liquor descends and runs away by another part and in the Weeck the Liquor is dispersed and carried away by the Flame which what it is and how it consumes bodies I shall on some other occasion by many luciferous Experiments manifestly prove something there is ascribable to the heat for that it may rarifie the more volatil and spirituous parts of those combustible Liquors and so being made lighter than the Air it may be protruded upwards by that more ponderous fluid body in the Form of Vapours But this can be ascribed to the ascension of but a very little and most likely of that only which ascends without the Weeck as for the Rising of it in a Spunge Bread Cotton c. above the superficies of the subjacent Liquor what has been said about the Filtre if considered will easily suggest a reason considering that all these bodies are bound with small holes or pores From this same Principle also viz. the unequal pressure of the Air against the unequal superficies of the water proceeds the cause of the accession or incursion of any floating body against the sides of the containing Vessel or the appropinquation of two floating bodies as Bubbles Corks Sticks Straws c. one towards another As for instance Take a Glass-jar such as A. B. in the 7th Figure and filling it pretty near the top with water throw into it a small round piece of Cork as C. and pâ—unge it all over in water that it be wet so as that the water may rise up by the sides of it then placing it any where upon the superficies about an inch or one Inch and a quarter from any side and you shall perceive it by degrees to make perpendicularly toward the nearest part of the side and the nearer it approaches it the faster to be mov'd the reason of which Phaenomenon will be found no other than this that the Air has a greater pressure against the middle of the superficies than it has against those parts that approach nearer and are contiguous to the sides Now that the pressure is not so much may as I shewed before in the explication of the 3 d Figure be evinced from the rising of the water near the sides higher than that in the middle Hence the Ball having a stronger pressure against that side of it which respects the middle of the superficies than against that which respects the approximate side must necessarily move towards that part from whence it finds least resistance and so be accelerated as the resistance decreases Hence the more the water is raised under that part of its way it is passing above