Liquors that are necessary to the nutrition and growth of Plants and by depraving those juices make the vegetables that are nourish'd by them unhealthy for the men that eat them or make drinks of them and these noxious Exhalations may be suppos'd in many places to impregnate the juices of the Earth much more copiously than they do the running or stagnant Waters lately spoken of because the difficulty of pervading the Earth in their ascent may so long check them as to make them very numerous in a small space and perhaps make them convene into Bodies so far of a Saline Nature as to be dissoluble either in common Water or some other Subterraneal Liquor by whose help as by vehicles they may insinuate themselves into the roots of Plants and be thence conveyed to other parts Divers things might be alledg'd to keep this conjecture from being improbable if I had leisure to insist on them but I I shall now only mention two things that on this occasion come into my mind the first whereof is that enquiring of a famous Chymist who liv'd in a Countrey abounding with Mines of Vitriol whether he did not observe that the Oaks growing over them were more solid or heavy than those Trees are elsewhere wont to be he answer'd me that he did and that the difference was remarkable The other is that the parts of some Minerals probably by reason of the smallness and solidity of the Corpuscles they consist of are capable of insinuating themselves very plentifully into the pores of growing Vegetables without being really subdu'd by what Philosophers are pleas'd to call the Concocting Faculty of the Plant and instead of being assimilated by the Vegetable they retain their own Mineral Nature and upon the recess or evaporation of the juice that serv'd them for a vehicle may sometimes discover their being Mineral even to an unassisted Eye For I remember I have seen a piece of a Vine that grew not far from Paris which being broken I perceiv'd a multitude of the internal Pores of the root and if I mistake not part of the Trunk also to be stuff't with Corpuscles of a Marchasitical Nature as manifestly appear'd by their Colour and their shining lustre and also by their weight There goes a Tradition among learned Men that the leaves of Vines that grow in some places of Hungary whose Mines afford Gold are as it were gilt on the lower side by ascending Exhalations of a Golden Nature whether this be true or no I shall not take upon me to determine but I remember that having made enquiry about the truth of it of a very ingenious Traveller whose Curiosity led him to visit heedfully those famous Mines he told me that he did not remember he had observ'd what is reported about the Leaves of the Vine but he knew very well that at Tockay a place that affords the famousest Wine of Hungary and indeed the best I have drunk very many of the kernels of the Grapes would appear guilt over as it were with leaf gold To what has been already discours'd may be added that since men are not wont to feed upon either Beasts or Birds of prey as carnivorous Animals usually are but upon such as live upon Grass or Seeds or other vegetable substances and drink nothing but fair water the noxious exhalations that make vegetables and water unwholsome may by their means have a very bad influence upon Sheep Cows Deer Pigeons and other Animals that seed upon such deprav'd vegetables and drink such noxious waters and consequently may be very hurtfull to those men that feed upon such Animals and may by the deprav'd aliment they afford determine them to an Endemical Disease such as that vitiated nutriment is fitted to produce Perhaps it will not seem improper to add on this occasion that 't is possible that in certain places the latent Minerals may be of such a Nature as that their Effluvia may instead of promoting hinder the Production of some particular Disease whether Epidemical or Endemical in the Bodies of them that inhabit those Places For as Physicians observe that the more manifest morbifick causes of some sicknesses are quite contrary to those of others so I think it not improbable that there may also be a mutual contrariety between those latent morbifick causes that are sent up by subterraneal Agents And therefore it need to be no wonder if some of these should either disable those to which they are Hostile or should at least work in Humane Bodies a great Indisposition to admit their hurtfull Operations which methinks those Physicians and Chymists should easily grant who with a boldness that I do not applaud prescribe Amulets wherein Arsenick or some other poysonous Drug is employ'd as preservatives from the Plague against which I doubt the chief Succours they afford proceeds from the Confidence or Fearlesness they give those that wear them But to return to our subterraneal Effluvia since there are divers whole Countries or lesser places that are either altogether or in great part free from this or that particular Disease as in several parts of Scotland from Agues especially if I mistake not Quartans are very unfrequent insomuch that a learned Physician answer'd me that in divers years practice he met not with above three or four and in several large Regions of the East-Indies notwithstanding the excessive heat of the Climate the Plague is very rare since I say these things are so it seems not altogether improbable that the subterraneal steaws may contribute to this advantage by impregnating both the Air the Earth and the Water with Corpuscles endow'd with Qualities unfriendly to these Diseases which seems to be somewhat the more credible because it has been observ'd that some vast Tracts of Land will neither breed nor maintain venemous Creatures as is undoubtedly believ'd of the whole Kingdom of Ireland where I confess I neither did see any alive nor met with any other that did for as to Spiders though they breed in that Countrey where I have seen many of them and sometimes even upon Irish Wood yet they are unanimously believ'd not to be poysonous there And some Writers tell us how truly I know not of some other Countries to which they affirm the like Privilege to belong But there is one instance afforded us by Begninus who travel'd much to visit Mines which if it be strictly true is very notable for my present purpose Dignum admiratione est says he quod quamvis in vicinia Hydriae Comitatus Gloriciensis ubi reperitur copiosè ☿ singulis ferè annis Lues pestifera grassatur illa tamen semper immunis ab hac manere soleat idque viri provectae aetatis se observasse à majoribus suis accepisse mihi sanctè confirmârunt To which I should add the Testimony of the Learned Michael Mayerus who pronounces Mercury to be an Alexipharmacum against divers Diseases and particularly the Plague if I did not suspect by his way
to deliver some few things that seem more favourable to my Conjectures than to his Opinion and were suggested to me partly by my own Thoughts and partly by the informations that to examine those Thoughts I procur'd by consulting some uncommon Authours and asking Questions of great Travellers and Navigatours By this means I came to learn that divers great Countries are usually free from the Plague that according to the vulgar Hypotheses ought to be as much subject to it if not more than England France Italy and those other parts of Europe and Asia where that fatal Disease rages from time to time in the parched Regions of Africk to which the Excessive Heats would make one expect that the Plagues should make far more frequent visits than to our temperate European Countries Leo Africanus informs us that some parts are so seldom afflicted with that dreadfull Disease that it usually spares the Inhabitants 29 or 30 years together And he expresly records that in Numidia it self if I much misremember not the Countrey 's name notwithstanding the raging heat of the Climate the Plague is wont to be produc'd but once in a hundred years Our Purchas informs us that in the Land of Negro's it is not known at all And to omit what some Travellers and Navigatours relate of Japan as if it were seldom or never invaded by the Pestilence I do not remember that in New England which contains a great extent of Land though I have had both Curiosity and opportunity to inquire after the Diseases of that Countrey I ever heard the English take any notice of the Plague since their setling there above threescore and ten years ago And as for the East Indies Sir Philibert Vernatti a Virtuoso of great fame and authority at Batavia where he resides in his ingenious Returns to the Queries sent him by the Royal Society of Naturalists answers thus to the fifteenth Pestis morbus est Indiarum Incolis incognitus The Plague is a Disease unknown amongst the Indians And of the Countries that lie yet more remote as the great Empire of China and the Kingdoms of Tunquin and of Cochinchina that great Traveller Alexander de Rhodes who spent 30 years in those parts affirms that the Plague is not so much as spoken of there And yet the same Jesuit does upon grounds probable enough estimate the number of the people of China alone to be two hundred and fifty millions a number I take to exceed by far that of all the Nations of Europe Now when I consider how vast Tracts of Land are compriz'd in those Countries some of which the Plague does not at all and others but exceeding unfrequently invade this Immunity seems to me very unfavourable to most if not all the opinions receiv'd among Physicians as also that of Diemerbroeck himself who derives the Plague from a Supernatural Cause the wrath of God against the sins of men For in Regions of such extent and divers of them very populous which are seated under very differing Climats and which are some of them inhabited by Nations that make war with numerous Armies fight bloudy battels leave heaps of unbury'd Bodies expos'd to the putrefying heat of the Sun are sometimes forc'd as well as others to live upon very unwonted and unwholsome foods that worship stocks and stones and beasts and some of them Devils whom they know to be such that are at least as guilty as Europeans of Assassinats Poisonings Rapes Oppression Sodomy and other crying Sins in these Regions I say 't is not imaginable but that great Intemperatures of the Air especially in point of Heat Stench of dead Bodies kill'd in fights unwholsomness of Aliments malevolent aspects of Celestial Bodies high provocations of the divine Justice and in short all the Causes to one or other of which the several parties of Physicians are wont to refer the Plague should be wanting any more than in our Europe and yet the Plague which is presum'd to be the Effect of one or other of those Causes is not here observed to be produc'd I know that it may be said that the Historical things I have been reciting do not onely oppugn the several receiv'd Opinions of Physicians about the cause of the Plague but disfavour my Conjectures too But if this be said I desire it may also be consider'd that my Judgment about the Plague consists of two Parts One that 't is exceeding difficult to assign the true and adequate Cause of the Origine of the Pestilence and the Other that whatever be the Cause of its First Eruption its Propagation and divers of its Symptomes may be probably enough refer'd to the depravation of the Air by Subterraneal Steams and their Effects If this be duly consider'd the Historical Observations will appear not to overthrow the First member of our Hypothesis but rather to confirm it and 't is upon this account that I have mention'd them in this place And as to the Second member it may be said that since in the East Indies and the other Countries I have nam'd as privileg'd from this raging Disease it is not observ'd to break out as it cannot be said that Subterraneal Effluvia do in those Countries promote the Propagation of it so it cannot be prov'd that they could not doe it incase the Plague were begun by other Causes But in regard I think it not improbable that sometimes the Plague is not onely fomented but begun by noxious Expirations of the Terrestrial Globe I shall add that this supposition though I confess it be somewhat disfavour'd by some of the lately mention'd Observations yet is not absolutely inconsistent with them For First it may be said that some of the Countries I speak of may be destitute of those noxious minerals to which we impute some Plagues it holding true in Minerals as well as in Plants Non omnis fert omnia tellus and to omit what I have not without some wonders observ'd of the Limits of differing sorts of Mines and Mineral Veins in very bordering parts of the same tract of Land I cannot but here take notice that though Sulphur be in many Countries usually found and that in plenty where there are other Metalline Veins insomuch that Chymists make it one of the three Principles of all Metals yet in the Mines of England more strictly so call'd I do not remember I ever met with so much as an Ounce of Native Sulphur and I could not find by divers Mineralists of whom I purposely ask'd the question that they had met with any among the various Mines they had frequented It may also happen that there may be hurtfull Minerals in a Countrey and yet not capable of often producing or promoting Pestilences there even upon moderate Earthquakes For 't is possible that these Orpimental or other Noxious Minerals may have their Beds or Veins lying so deep in the Earth that they are not ordinarily able to send up Effluvia strong and copious enough to make
Countrey which abounding with veins of Cinnabar was probably by their expirations preserved from the Pestilence And our Hypothesis will perhaps appear somewhat the more probable if we reflect on what I lately mention'd of the sudden check that is almost every Summer given to the Plague which at that time is wont to reign at Grand Cairo For since 't is generally observ'd and complain'd of that Morbifick Causes doe their work much more effectually than Sanative ones It seems very probable that Exhalations ascending from under-ground into the Atmosphere may be capable of producing pestilential Fevers and the Plague it self since those Corpuscles that impregnate the Egyptian Air upon the swelling of the Nile are able to put a speedy stop not onely to the contagiousness but to the malignity of the Plague even when 't is assisted by the Summer Heat which at Grand Cairo is wont to be excessive But having insisted perhaps too long on this Egyptian Pestilence I shall onely add by way of Illustration of the Conjecture that invited me to mention it that the accession even of Expirations that are not themselves wholsome may sometimes serve to correct the Air and put a sudden check to an Epidemical Disease For Corpuscles of differing kinds may by their Coalitions acquire new Qualities and each sort of them lose some of those they had before as suppose there wander'd in the Air a great many Effluvia which by their determinate shape and bulk were apt to corrode or irritate the Lungs or the Membranes of the Brain c. as those of Nitre are to corrode Silver it may happen that another sort of Reeks though in their own nature unwholsome may by associating themselves with the first sort and composing with them Curpuscles of new qualities abolish or much weaken the noxious ones they had before in reference to this or that part of the Humane Body Though the Spirits of Salt-peter will readily corrode Silver yet if you add to them as for some purposes I am wont to do about half as much or less of the spirituous Particles of common Salt which yet are corrosive enough and will fret asunder the parts of Iron Copper Antimony c. there will emerge a Body that will not at all corrode pure Silver PROPOSITION IV. T is very probable that most of the Diseases that even Physicians call New ones are caus'd either chiefly or concurrently by Subterraneal Steams THE Product of my first Endeavours to bring credit to the foregoing Proposition appearing to have miscarry'd when I came to send to the Press the things I had written about it that at least what can be preserv'd of it may not be lost I shall substitute in stead of it the following Account At the entrance of my Discourse I observ'd that the Term new Disease was much abused by the Vulgar who are wont to give that Title to almost every Fever that in Autumn especially varies a little in its Symptoms or other Circumstances from the Fevers of the foregoing Year or Season And therefore I declared that by new Diseases I meant onely such whose Symptoms were so uncommon that Physicians themselves judged them to deserve that appellation Such for instance as the Sudor Anglicus or Sweating Sickness that Disease which the learned Wierus and others call in Dutch Die Varen an unheard-of Disease describ'd by Ronseius that in the Year 1581 invaded and destroy'd many in the Dukedom of Lunenburg to which many Physicians add the Rickets and others generally the Lues Venerea Having clear'd the Terms I next consider'd whether there were really any new Diseases properly so call'd and gave some reasons to suspect that some Diseases which among Physicians themselves have pass'd for New were extant before in rerum natura though not in the Countrey wherein even the learned judg'd them to be new And I intimated that to examine this Suspicion throughly 't is not safe to acquiesce in the Books of Physicians onely but 't is fit to consult the Writings of Geographers whether ancient among whom I particularly recommended Strabo or Modern together with the Relations of Historians Navigators and other Travellers And here I inquired without determining any thing whether the Lues Venerea be as most Physicians are wont to suppose a Disease wholly new or onely new to our European World and brought hither from some African or other remote Region where it may be probably suspected to have long been Endemical But taking it for granted with the generality of Physicians that some new Diseases are to be admitted I advanced to consider some of the Causes to which they may be imputed And to give some reasons why I do'nt acquiesce in their Opinion though very general that derive them onely or chiefly from the varying influences of the Heavenly Bodies For the most powerfull of those namely the Sun and Moon act in too general and indeterminate a way to afford a sufficient account of this affair And as for the other Lights the fixt Stars besides their being universal and indefinite agents their scarce measurable remoteness makes it justly questionable whether they have any sensible Operation upon any part of our Bodies save our Eyes And though I deny not that great intemperateness of the Air as to the four first Qualities as Heat Cold Driness and Moisture are wont not over justly to be call'd may dispose mens Bodies to several great Distempers and may also be concurrent causes of those we are speaking of yet neither can I acquiesce in these when I consider how much more frequently they happen than new Diseases do and that their action though various is too general and indeterminate to perswade me that they can be the adequate causes of effects so rare and anomalous as Diseases odd enough to deserve the Title of new But now the Subterranean Region of our Globe besides that it is always near us abounds with variety of noxious Minerals and probably conceals great quantities of differing sorts of them that are yet unknown to us And since we have elsewhere proved that there want not causes in the Bowels of the Earth to make great and irregular and Sometimes sudden Confluxes Conflicts Dissipations and other considerable Changes amongst the Materials that nature has plentifully treasured up in those her secret Magazins And since in making out the three former Propositions we have manifested that the Subterraneal parts of the Globe we inhabit may plentifully send up Noxious Effluvia of several kinds into the Air it ought not to seem improbable that among this Emergent variety of Exotick and hurtfull Steams some may be found capable to disaffect Humane Bodies after a very uncommon way and thereby to produce new Diseases whose duration may be greater or smaller according to the lastingness of those Subterraneal causes that produce them On which account it need be no wonder that some new Diseases have but a short duration and vanish not long after there appearing the Source or
AN ESSAY Of the Great EFFECTS OF Even Languid and Unheeded MOTION Whereunto is Annexed An Experimental Discourse of some little observed Causes of the Insalubrity and Salubrity of the Air and its Effects By the Honourable ROBERT BOYLE Fellow of the Royal Society LONDON Printed by M. Flesher for Richard Davis Bookseller in Oxford 1685. ADVERTISEMENT OF THE Publisher T IS thought fit the Reader should be inform'd That the insuing Tract about the Effects of Languid Motions was design'd to be a Part of the Authour's Notes about the Origine of Occult Qualities and should have come abroad together with the Papers about the Effluvia of Bodies most of which are already publish'd And accordingly it was printed seven or eight years ago which Circumstance is here mention'd to give a Reason why several Particulars were omitted in the Body of the Discourse that will be found annex'd to the End of it For these occurring to the Authour whilst he cursorily read over the Tract it self when it was upon the point to be made publick 't was thought fit rather to subjoin them by way of a short Appendix than to let any thing be lost that seem'd pertinent to so difficult and uncultivated a Subject as That they belong to The Reader is farther to be advertis'd That of the Three Preliminary Discourses which the Authour intended for Introductory Ones to What he design'd to say more particularly about the Mechanical Origine or Production of Occult Qualities One was concerning the Relations betwixt the Pores of Bodies and the Figures of Corpuscles but that the great Intrieacy and Difficulty He found in this copious Subject made Him consent That the Discourse of Local Motion which should have accompany'd it to the Press should be printed long before it And those Papers about Pores and Figures having been for a great while out of the Authour's Power He now to gratify the Stationer with something that may in Their stead make up the formerly printed Essay a Book of a convenient Bulk has put into his Hands what now comes forth about some Unheeded Causes of the Healthfulness and Insalubrity of the Air which being chiefly attributed to Subterraneal Steams Subtile and for the most part Invisible are as near of kin to the other Effluviums treated of in the Introductory Discourse as is requisite to keep the mention that is made of them in this Book from appearing very incongruous AN ESSAY Of the Great EFFECTS Of Even Languid and Vnheeded LOCAL MOTION CHAP. I. HOW superficially soever the Local Motion of Bodies is wont to be treated of by the Schools who admit of divers other Motions and ascribe almost all strange things in Physicks to Substantial Forms and Real Qualities yet it will become Us who endeavour to resolve the Phaenomena of Nature into Matter and Local motion guided at the beginning of things immediately and since regulated according to settled Laws by the Great and Wise Author of the Universe to take a heedfull notice of its kinds and operations as the true Causes of many abstruse Effects And though the industry of divers late Mathematicians and Philosophers have been very laudably and happily exercised on the nature and general Laws of this Motion yet I look upon the Subject in its full extent to be of such importance and so comprehensive that it can never be too much cultivated and that it comprises some parts that are yet scarce cultivated at all And therefore I am not sorry to find my self obliged by the design of these Notes written as you know to facilitate the explicating of Occult Qualities to endeavour to improve some neglected Corners of this vast field and to consider Whether besides those effects of Local motion which are more conspicuous as being produced by the manifest striking of one body against another where the bulk c. of the Agent together with its Celerity have the chief Interest there may not be divers effects wont to be attributed to Occult Qualities that yet are really produced by faint or unheeded Local motions of bodies against one another and that oftentimes at a distance But before I enter upon particulars this I must premise in general which I have elsewhere had occasion to note to other purposes that we are not to look upon the bodies we are conversant with as so many Lumps of Matter that differ onely in bulk and shape or that act upon one another merely by their own distinct and particular powers but rather as bodies of peculiar and differing internal Textures as well as external Figures on the account of which structures many of them must be considered as a kind of Engines that are both so framed and so placed among other bodies that sometimes Agents otherwise invalid may have notable operations upon them because those operations being furthered by the Mechanism of the body wrought on and the relation which other bodies and Physisical Causes have to it a great part of the effect is due not precisely to the external Agent that 't is wont to be ascribed to but in great measure to the action of one part of the body it self that is wrought on upon another and assisted by the concurring action of the neighbouring bodies and perhaps of some of the more Catholick Agents of Nature This Notion or Consideration being in other Papers particularly confirmed I shall not now insist upon it trusting that you will not forget it when there shall be occasion to apply it in the following Notes There may be more Accounts than we have yet thought of upon which Local motions may perform considerable things either without being much heeded or without seeming other then faint at least in relation to the considerableness of the Effects produced by them And therefore I would not be understood in an exclusive sense when in the following Discourse I take notice but of a few of the above-mentioned Accounts these seeming sufficient whereto as to Heads may be conveniently enough referred the Instances I allot to this Tract And concerning each of these Accounts I hold it requisite to intimate in this place that I mention it onely as that whereon such effects of Local motion as I refer to it do principally depend for otherwise I am so far from denying that I assert that in divers cases there are more Causes than one or perhaps than two of those here treated of apart that may notably concur to Phaenomena directly referred to but one or other of them To come then closer to our subject I shall take notice That among the severall things upon whose account men are wont to overlook or undervalue the efficacy of Local motions that are either Unheeded or thought Languid the chief or at least those that seem to me fittest to be treated of in this Paper are those that are referable to the following Observations CHAP. II. Observat I. Men are not usually aware of the great efficacy of Celerity even in small Bodies and especially if they
supervening of the Cold. And the expansive endeavour of freezing water is not onely capable of doing this but of performing so much greater things which I elsewhere relate that my trials have made me sometimes doubt whether we know any thing in nature except kindled Gunpowder that bulk for bulk moves more forcibly though the motion seems to be very slow CHAP. V. Of the Propagable Nature of Motion Observat IV. Men are not sufficiently aware how propagable Local Motion is even through differing Mediums and Solid bodies THere are four principal Occasions on which I have observed that men are wont to think the Communicating of Motion much more difficult than indeed it is And first there are many that observing how usually those bodies that hit against hard ones rebound from them easily perswade themselves that Motion can scarce be transmitted or diffused through Solid bodies But though it be true that oftentimes in such cases the progressive motion of the body or the Solid that is struck or impelled be either inconsiderable or perhaps not so much as sensible yet the impulse may make a considerable impression and may be communicated to a great share of the particles of that matter whereof the solid mass consists as we see in the striking of a timber-beam at one end the motion though perhaps it were not strong at the first may become sensible at the other Though Bell-metal be so hard a body that it is reckoned harder than iron it-self insomuch that oftentimes it resists even files of Steel which readily work on Iron yet this solidity hinders not but that as I have found conveniently shaped vessels of Bell-metal though thick will be sensibly affected by a motion that neither is strong nor touches them in more than a short line or perhaps than a Physical point The truth of this I have found by trial on more than one such vessels and particularly on one that was hemisphaerical which being placed or held in a convenient posture if I did but gently pass the point of a pin for a little way along the brim of it it would sensibly resound and that to a very attentive ear so long and in such a ringing manner as made it highly probable that the parts immediately touched and not so much as scratched by the point of a pin were not onely put into a vibrating motion themselves but were enabled to communicate it to those that were next them and they to those that were contiguous to them and so the tremulous motion was propagated quite round the bell and made divers successive Circulations before it quite ceased to be audible And if in stead of drawing a Line on the brim of the vessel I struck it though but faintly with the point of a pin though the part immediately touched would be but a physical point yet the motion would be like the former propagated several times quite round as was argued by the ringing and duration of the produced sound though this metalline vessel were seven inches in Diameter and of a considerable thickness Nor was a solidity like that of Brass requisite to produce these effects For I found them to insue much after the same manner when I employed onely a short and slender thread of Glass which though little if at all thicker than a pin was yet hollow quite through Now if it be true as 't is highly probable that Sound as it belongs to the air consists in an undulating motion of the Air and so in our case requires a vibrating motion in the sonorous body to impart that motion to the Air we must grant in our Instances a wonderfull propagableness of motion even when 't is not violent in Solid bodies themselves since the point of a pin gently striking a part no bigger than it self of a mass of very solid metal could thereby communicate a sensible motion and that several times circulated to millions of parts equall to it in bulk and much exceeding it in hardness And since the effect was more considerable when the trial was made in a much greater than in a smaller vessel 't is probable that if I had had the opportunity of experimenting on a large and well-hung Bell the Phaenomenon would have been more notable as it also seemed to be on our vessel if in stead of striking it with the point of a pin we cast though but faintly against the lower part of it a grain of shot less than a small pins-head or let a little grain fall from about one foot high upon the inside of the inverted Hemisphere And to shew that even soft and yielding bodies and but faintly moved are not to be excluded from a power of putting such hard ones into motion I shall add that I found almost the like effects to those above mentioned by passing the pulp of my finger a little way along the lower part of the vessel Nay that fluid bodies themselves may communicate such an intestine and propagable motion to harden solid ones I may have hereafter an occasion to shew by the effects of a small Flame and the Sun-beams on glass and steel And I shall here on this occasion add this word about the Propagation of Motion produced in solid bodies by heat that it much depends upon the particular Textures of the bodies For I found that when I heated a piece of glass or of a fire-stone I could without inconvenience hold my naked hand upon parts that were very near suppose within an inch off the ignited portions of them But if we take a rod of Iron for instance and heat one end red-hot the heat of that end will be so propagated towards the other that it will offend one's hand at several times the distance at which one might conveniently hold the rod if it were of glass In many buildings it may be observed and is thought a sign of the firm Cohesion of their parts that a stamp of one's foot nay or bare treading or some such other lesse brisk impulse made in one room will have a sensible effect in all or most of the others And it often happens that by the hasty shutting of a door the whole house is made to tremble whence we may argue that even among solid bodies motion made in one place may be readily propagated to many others And if as to the latter of the Instances the sudden impulse and compression of the Air made by the door supposed to be hastily shut have any considerable share in the effect the Phaenomenon will serve to shew the efficacy even of such a motion of a fluid body as we cannot directly feel upon divers large and firmly connected solid bodies In Earthquakes the tremulous motion sometimes extends so very far that though it seems highly probable that the shake that is given to one part of the Earth by the firing and explosion of subterraneal exhalations if that be the true and onely cause of Earthquakes is not capable of reaching near so
far as divers Earthquakes have done but that the fire passes through some little subterraneal clefts or channels or hidden conveyances from one great Cavity or Mine to another yet 't is not improbable but that the vehemently tremulous motion does oftentimes reach a very great way beyond the places where the explosions were made Since though Seneca would confine the extent of Earthquakes to two hundred miles yet observations made in this and the last Century warrant us to allow them a far greater spread The Learned Josephus Acosta affirms that in the Kingdom of Peru in the year 1586 an Earthquake reached along the shoar of the Pacifick sea 160 Leagues and adds that sometimes it has in those parts run on from South to North 300 Leagues And in the beginning of this our age Anno Dom. 1601 good writers relate a much larger Earthquake to have happened since it reached from Asia to that Sea that washes the French Shoars and besides some Asiatick Regions shook Hungary Germany Italy and France and consequently a great part of Europe And if that part of the Narrative be certain which relates that this lasted not much above a quarter of an hour it will be the more likely that this Earthquake shook great Tracts of Land beyond those places to which the fired matter passing from one cavity to another could reach in so short a time As you will the more easily guesse if you try as I have done that in trains of Gunpowder it self the fire does not run on near so swiftly as one would imagine But though I have been in more Earthquakes then one yet since they were too sudden and too short to afford me any considerable observation I shall say no more of them but proceed to take notice that oftentimes the motion of a Coach or Cart that passed at a good distance from the place that I was in has made the buildings so sensibly shake that I could not but wonder that so great a portion of so firm and sluggish a body as the Earth could by a cause that seemed very disproportionate to such an effect be made to tremble it self and manifestly to shake firm buildings that were founded on it And this observation made me the more inclinable to give credit to their Relations who tell us that in a calm night the march of a troup of horse may be felt by attentive Scouts watching at a great distance off by the shake that the ground receives from the trampling of the horses though I formerly suspected much and do yet a little that the impulse of the air conveyed along the resisting surface of the ground might mainly contribute to the effect that is ascribed onely to the motion of the soil Before I advance to the Second Member of this Chapter it may not be impertinent to note that in peculiarly disposed bodies and especially in Organical ones a very languid motion may have a far greater effect than it could produce by a bare propagation of it self For it may so determine the motion of the Spirits or other active parts of the body it works on as to make multitudes of them act as if they conspired to perform the same motions As when a ticklish man by having the pulp of one's finger passed gently along the sole of his foot or the palm of his hand has divers muscles and other parts of his body and face put into preternatural or unusual motions And most men by being lightly tickled with the end of a feather or straw within their Nostrils have their heads and many parts of their bodies put into that violent Commotion wherein Sneezing consists And I remember that having for some time been by a distemper from which God was graciously pleased a while after to free me quite deprived of the use of my hands it more than once hapned to me that sitting alone in a Coach if the wind chanced to blow a single hair upon my face in the Summer-time the tickling or itching that it produced was so uneasy to me 'till by calling out to a footman I could get it removed that though I could well bear it as long as I was wont to do when having the use of my hands I could relieve my self at pleasure yet if I were forced to endure the itching too long before any came to succour me the uneasiness was so great as to make me apprehend falling presently either into Convulsions or a Swoon But 't is time to proceed to the second Member of this Chapter 2. Others there are that cannot believe that Local motion especially if it be languid can be propagated through differing Mediums each of which save that wherein the Motion is begun must they think either repell or check and dead it To these I shall recommend the Consideration of an Experiment I remember I made before some Learned men in our Pneumatick Engine For having caused a large and thick glass Receiver to be so blown that it had a glass button in the inside of that part which upon the Engine was to be placed upwards I caused a Watch to be suspended by a little Silverchain fastned to that button by as slender and soft a body as I thought would be strong enough to support my watch and then the Glass being cemented on close to the Receiver to prevent a Commerce between the Cavity of it and the Air the watch that hung freely near the middle of the Cavity of the Receiver made it self to be heard by those attentive Listners that would hold their ears directly over the suspended watch whose motions were thereby argued to have been propagated either through the included air or along the string to the concave part of the Glass and through the whole thickness of the Glass to the convex part and thence through the interposed air to the Ear. And this mention of watches minds me of what I often observed in a small striking watch that I have worn in my pocket For when it struck the Hours and in some postures when the balance did but move I could plainly feel the brisker motions of the Bell and sensibly the languid ones of the balance through the several linings of my Breeches and some other interposed soft and yielding bodies and this though the watch as I said was small and the balance included in a double case and though the outwardmost were of what they call Chagrine and the innermost of Gold which I therefore mention because that closest of metals is observed more to dead sounds and motions than harder metals as Silver Copper and Iron That Motion may be propagated through differing Mediums may seem the more probable by the shakings that are often felt by men lying on beds that stand in rooms close shut when loud claps of thunder are produced perhaps at a great distance off in the clouds And whether it will be fit to add to this Instance that which you have lately met with in the III. Chapter
the peculiar modification of the others motion THough the Experiments delivered in the foregoing Chapter have I presume sufficiently manifested that the modification given to the motions of the Air by sonorous bodies may have considerable effects upon Animals in whose organized bodies the curiously contrived parts have an admirable connexion with and relation to one another and to the whole Symmetrical fabrick they make up yet I fear it will scarce seem credible that sonorous motions of the Air not very loud should find even in bodies Inanimate and Inorganicall such congruous Textures and other Dispositions to admit their action that even more languid Sounds peculiarly modified may sensibly operate upon them and much more than sounds that are louder and more vehement but not so happily modified To make this good by particular Experiments I shall begin with that which though the effect may seem inferiour to that of most of the others I judge fittest to manifest that the produced motion depends upon the determinate modification of that of the impellent Fluid That a certain impulse of Air made by one of the Unison-strings of a Musical Instrument may suffice to produce a visible motion in another is now become a known experiment of the Cause and some unobserved Phaenomena of which I elsewhere more fully discourse But that it may not be suspected in this case that the shake of the untouched string is communicated to it by the propagated motion of the Instrument it self to which the string that is struck is also fastned I shall add that according to what I elsewhere relate I found by trial purposely made that a string of Wire which you will grant to be a more solid body than an ordinary Gut-string may be without another string brought to tremble by a determinate Sound made at a distance which produced but such an impulse of the Air as could neither be seen nor felt by the By-standers nor would communicate any sensible motion to the neighbouring strings 'T is true that in this case the string in which the trembling was produced was a single long slender and springy body fastned at both ends to a stable one and therefore it may seem altogether groundless to expect that any thing like this effect should be by the same cause produced in bodies that do not appear so qualified But as we elsewhere shew that a certain degree or measure of tension is in order to this Phaenomenon the principal Qualification without which all the other would be unavailable perhaps 't will not be absurd to enquire whether in bodies of a very differing appearance from strings the various Textures Connexions and Complications that Nature or Art or both may make of the parts may not bring them to a state equivalent to the Tensions of the strings of Musical Instruments whereby divers of the mentioned parts may be stretched in the manner requisite to dispose them to receive a vibrating motion from some peculiar Sounds And whether these trembling parts may not be numerous enough to affect their neighbours and make in the body they belong to a tremulous motion discernible though not by the Eye yet by some other sense This conjecture or inquiry you will I hope have the less unfavourable thoughts of when you shall have considered the following Experiments I remember that many years agoe I found by trial that if a somewhat large and almost hemispherical Glasse though not very thin were conveniently placed a determinate sound made at a convenient distance from the concave surface of the Glasse would make it sensibly ring as a Bell does a while after it has been struck But this noise was the effect of a determinate sound for though the voice were raised to a higher tone or if the sound were made louder the same effect would not insue I remember also thâ—â— some years after I observed that large empty drinking-glasses of fine white metal had each of them its determinate Tension or some disposition that was equivalent as to our purpose For causing the strings of a Musical Instrument to be variously screwed up and let down and briskly struck we found as I expected that the motion of one string when 't was stretched to a certain note or tone would make one of the Glasses ring and not the other nor would the sound of the same string tuned to another note sensibly affect the first Glasse though perhaps it might have its operation upon another And this Circumstance is not on this occasion to be omitted that after we had found the tone proper to one of the Glasses and so tuned the string that I say when that was struck the Glasse would resound Having afterwards broken off a part of the foot of the glass yet not so much but that it continued to stand upright the same sound of the string would no longer be answered by the Vessel but we were obliged to alter the tension of the string to produce the former effect The Learned Kircherus as I have been informed somewhere mentions a correspondence between some liquours and some determinate sounds which I suppose may be true though the triall did not succeed with me perhaps for want of such accommodations for so nice an Experiment as I could have wished but could not procure But if you can you will oblige me to make the trials so as to satisfie your self and me whether the agitation of the liquour be caused immediately by the motion of the Air or be communicated by the intervention of the tremblings of the Vessel An Artist famous for his skill in making Organs answered me that at some stops of the Organs some seats in the Church would tremble But because I suspected by his Relation that the greatness of the sound chiefly effected it because when that Pipe which they call the open Diapason sounds the chair or seat on which the Organist sits and perhaps the neighbouring part of the Organ trembles I shall add that I have divers times observed certain sounds of an excellent Organ to make not onely the seat I sate on in the Church tremble under me but produce an odd tremulous motion in the upper part of my Hat that I could plainly feel with my hands And that which makes me apt to believe that this effect depends upon the determinate tone rather than upon the loudness of the sound is that I have oftentimes felt and diligently observed such a kind of motion in the upper part of my Hat upon the pronouncing of some words in ordinary discourse in which case the effect could not with probability be referred to the greatness of the Sound but its peculiar fitness to communicate such a motion to a body so disposed Nor is it onely in such small and yielding bodies as Hats and Strings that Sounds that are not boisterous may produce sensible effects for if they be congruous to the Texture of the body they are to work on they may excite motions in it though it
I have propos'd it will not much concern this Discourse to examine the Allegation for whatever the latent Cause of the Phaenomena may be the manifest Circumstances of them suffice to shew that bodies which as to sense are in a natural state of Rest may be in a violent one as of Tension and may have either upon the score of the contexture of the parts among themselves or upon that of some interfluent subtile matter or some other Physical Agent a strong endeavour to fly off or recede from one another and that in divers bodies the cause of this endeavour may act more vigorously than one would easily believe and this suffices to serve the turn of this Discourse For I presume that a person of your Principles will allow that Local Motion must be produc'd by Local Motion and consequently that without a very strong though invisible and unheeded one such hard and solid bodies as thick pieces of metall could not be made to crack I know not whether I may on this occasion acquaint you with an odd Relation I had from a very honest and credible as well as experienced Artist whom I for those reasons have several times made choice to deal with about precious Stones and other things belonging to the Jewellers and Goldsmiths trades For considering with him one day a large lump of matter which contained several Stones that he took for course Agats and which were joyned together by a Cement that in most places was harder than most ordinary Stones I perceived that there remained divers pretty large cavities in this Cement which seemed to have contained such Stones as those that yet made parts of the lump Upon which occasion he affirmed to me that several of the Stones grew whilst they were lodg'd in those cavities And when I told him that though I had been long of an opinion that Stones may receive an increment after their first formation yet I did not see how any such thing appeared by those we were looking upon He gave me in many words an account of his Assertion which I reduced to this that the Stones he spoke of did after they were first formed really tend to expand themselves by virtue of some Principle of growth which he could not intelligibly describe but that these Stones being lodg'd in a Cement extreamly hard and therefore not capable of being forced to give way their expansive endeavour was rendered ineffectual but not destroyed so that when afterwards these Stones came to be taken out of the Cement wherein they were bedded and to whose sides 't is like they were not exquisitely congruous the comprest Stones having their sides now no longer wedged in by the harder Cement quickly expanded themselves as if 't were by an internal and violently comprest spring and would presently burst asunder some into two and some into more pieces of which he presented many to his friends but yet had reserved some whereof he presented me one that I have yet by me together with some of the mass whose Cement I find to bear a better polish than marble and to be very much harder than it And in answer to some questions of mine he told me that he had taken up these Stones himself naming the place to me which was not very far off and that he observed all that he told me himself and more than once or twice and that I needed not suspect as I seemed to doe that 't was the strokes employed to force the Stones out of their Beds that made them break For besides that many of them which it seems were not comprest enough did not break several of those that did were taken out without offering them any such violence as that their bursting could with any probability be imputed to it CHAP. IX Observat VIII One main cause why such Motions as we speak of are overlook'd is That we are scarce wont to take notice but of those motions of Solid bodies wherein one whole Body drives away another or at least knocks visibly against it whereas many effects proceed from the intestine motions produced by the external Agent in and among the parts of the same body THis Observation is like to be much more readily understood than granted and therefore I shall offer by way of proof the following Experiments We caused in a large brass Stop-cock the movable part to be nimbly turned to and fro in the contiguous cavity of that part that was made to receive it in that part of the Instrument that is wont to be kept fixt And though this motion of the Key were made onely by the bare hand yet in a short time the mutual attrition of the contiguous parts of the Instrument made so brisk an agitation in the other parts that the incalescence made the metal it self to swell insomuch that the Key could no more be turned but remained fixt as if it had been wedged in so that to make it work as before it was necessary by cooling it to make it shrink a little and so take off the mutual pressure of the Key and the other part of the Stop-cock Nor is this to be looked on as a casual Experiment for besides that it was made more than once and is very analogous to some other trials of mine I found that a maker of such Instruments complained to me that he was several times forced to intermit his work and plunge his Instrument in cold water before he could by grinding adjust the Key to the cavity it ought to fit I presume I need not take notice to you that this Experiment confirms what I elsewhere mention of the dilatation of metals themselves by Heat and therefore I proceed to the next Instance This is afforded by the known Experiment of passing one 's wetted finger upon the orifice of a Drinking-glass almost fill'd with water For though the Eye does not immediately discern any motion that by reason of the pressure of the finger is made by one part of the glass upon another yet That a vibrating motion is thereby produced may be argued by the dancing of the water especially that which is contiguous to the prest sides of the glass by which 't is oftentimes so agitated that numerous drops are made to leap quite over and others are tossed up to a good height into the Air. And that there may be considerable motions in the sides of the glass whilst it does not break in pieces we may probably guess by this that in Drinking-glasses artificially cut by a spiral line both I and others have often found by trial that a glass being dextrously inverted and shaken the parts will vibrate up and down so manifestly as sometimes to lengthen the glass by my estimate a quarter of an inch or more and yet the glass being set again upon its foot it appeared that it had not been hereby at all injured That two pieces of Iron or Steel by being strongly rubbed against one another will at length acquire
malignity of the Plague yet I doubt they are not sufficient for so wonderfull an effect unless we take in some new Exhalations that then impregnate and correct the Air. And we shall scarce doubt of the great interest these have in the effect produc'd if we give credit to what the recentest Writer I have met with of Voyages into Egypt has lately publish'd about the annual Pestilence at Grand Cairo a City he much frequented This Authour in the account he gives of the present state of Egypt relates that a little after the middle of our June and usually upon the very seventeenth day there begin to fall towards the last quarter of the night near the morning certain drops of a kind of Dew which causes the River to be fruitfull and purifies the Air from all the Infection of Camsims by which I presume he means the Pestilence for after some lines interpos'd he subjoins The Drops or Dew purifies the Air for as soon as it falls the Plague ceases to be mortal none dies of it the Air is wholesome all Distempers cease and if any person grows sick he never dies And then he adds This Dew gives life to every thing and when it falls upon the Wheat it causeth it to continue many years without corruption or Worms and is far more nourishing than that Corn on which it never falls For this cause they never house the Corn of the Grand Seignior in the Barns till this Dew is fallen upon it that it might keep the longer without Worms As well this Conjecture as some other things deliver'd here and there in this Paper about the Salubrity of the Air may probably gain the more credit if I here subjoin what I learn'd by inquiry from a very ingenious Gentleman who was owner of one or more of the Mines that afford the Phaenomenon I am to mention Which is this That in the Tin-mine Countreys in Devonshire it sometimes happens as perhaps I may have elsewhere noted to another purpose that upon a sudden a Spot of ground and that not always narrow will be as 't were blasted by the ascending hurtfull Fumes insomuch that not onely the Grass Fern and other more tender Vegetables will be turned black and as it were burnt or scorched up but now and then Trees also without excepting Oaks themselves will be blasted and spoil'd by the powerfull Operation of these subtil and poisonous Effluvia It will probably be here expected that among the Epidemical Diseases that our Hypothesis derives from Subterraneal Effluvia I should particularly treat of the cause of Pestilential Fevers and the Plague it self But though some such Fevers may not improbably be in great part imputed to the noxious Expirations of the Globe we inhabit yet as to the true Plague it self I freely confess I am at a loss about it's Origine The sacred Writings expresly teach that some Plagues and particularly that which in David's time swept away in three days 70000 Persons have been in an extraordinary manner inflicted by God And to me it appears either scarce possible or far more difficult than those that have not attentively enough considered the matter are wont to think it To deduce the abstruce Origine strange Symtomes and other odd Phaenomena of some Plagues that are recorded in History from merely Corporeal Causes On the other side it seems unphilosophical and perhaps rather seems than is very pious to recur without an absolute necessity to Supernatural Causes for such Effects as do not manifestly exceed the power of Natural ones though the particular manner of their being produc'd is perchance more than we are yet able clearly to explicate And I think it the more questionable whether all Plagues are Supernatural Exertions of God's Power and Wrath against the Wicked because I observe that Brutes which are as well uncapable of moral Vice as moral Vertue are yet oftentimes subject to Murrains such as may without incongruity be lookt upon as the Pestilences of Beasts And 't is the less likely that these sweeping and contagious Maladies should be always sent for the punishment of impious men because I remember to have read in good Authours that as some Plagues destroy'd both Men and Beasts so some other did peculiarly destroy Brute Animals of very little consideration or use to Men as Cats c. Upon these and the like Reasons I have sometimes suspected that in the Controversie about the Origine of the Plague namely Whether it be Natural or Supernatural neither of the contending Parties is altogether in the right since 't is very possible that some Pestilences may not break forth without an extraordinary though perhaps not Immediate interposition of Almighty God provok'd by the Sins of Men and yet other Plagues may be produc'd by a Tragical concourse of merely Natural Causes But though the difficulties that incumber each of the opposite Opinions keep me both from Dogmatically asserting that All Plagues have a Supernatural Origine and from denying that Any have it yet to say something on such an occasion though I can speak but very hesitantly I shall venture to add that whether or no the true Plague be said to descend to the Earth from a higher Sphere than that of Nature yet its Propagation and Effects are at least for the most part carry'd on mainly by a malignant disposition in the Air without which some Plagues could never have been so catching as they were nor so suddenly mortal and that in divers Pestilences this malignant Disposition in the Air may probably be in great part imputed to some kinds of Subterraneal Expirations I am prone to think and that chiefly upon two Accounts The first thing that induces me to this Conjecture is that not any of the several Causes to which the Plague is wont to be imputed seems to me to be sufficient Those that fetch it from the malevolent aspects and influence of the Celestial lights besides that they suppose some things very difficult to be prov'd have recourse to Agents too remote too general and too indeterminate to be acquiesc'd in as the Causes of such particular Symtomes and Phaenomena as oftentimes accompany Pestilences And as for those other Sects of Physicians that confidently derive the Plague some from Internal Putrefaction and others from excessive Heats noisome Stinks Corrupt aliments and such other Celebrated Causes though each party alledges plausible Reasons for its own opinion yet their objections against their adversaries are much stronger than their arguments are for themselves And the Learned Diemer-broeck though his own Hypothesis seem to be more Theological than Philosophical has much enervated the Arguments brought for the several opinions lately nam'd and by him dissented from The Reasons he employs to refute all the receiv'd opinions about the Origine of the Plague except his own are divers of them worthy of so learned a man to whom though I had leisure to transcribe them I should refer the Curious my present design being onely
that when he walked over the neighbouring Grounds he found himself much disorder'd especially in his Thorax by the Effluvia and that the Mine-men and Diggers were subject to a malignant anomalous and dangerous sort of Fevers though he said he was apt to impute I know not how truly some part of their obnoxiousness to it to their drinking too much strong Wine But though 't is probable the Effluvia of Orpimental Bodies may have a great interest in several Plagues yet I strongly suspect that many others may proceed from the steams of such Subterraneal Bodies as are not yet distinctly known to us and possibly have their Effluvia variously combin'd either beneath or above the surface of the Earth I say above because I have several times and that without heat combin'd separately invisible fumes of differing kinds into manifestly visible ones in the free and open Air. And that the Subterraneal Effluvia may produce effects and therefore probably be of natures very uncommon irregular and if I may so speak extravagant may appear in those prodigious Crosses that were seen in our time viz. in the Year 1660. in the Kingdom of Naples after an eruption of the fiery Mountain Vesuvius of which Prodigies the Learned Kircherus has given an account in a particular Diatribe For these Crosses were seen on Linen Garments as Shirt-sleeves Womens Aprons that had lain open to the Air and upon the expos'd parts of Sheets which is the less to be admired because as Kircher fairly guesses the mineral vapours were by the texture that belongs to Linen which consists of threads crossing one another for the most part at or near right Angles easily determin'd to run along in almost streight lines crossing each other and consequently to frame Spots resembling some one and some another kind of Crosses These were extremely numerous in several Parts of the Kingdom of Naples insomuch that the Jesuit that sent the Relation to Kircher says that he himself found thirty in one Altar-cloth that fifteen were found upon the Smock sleeve of a Woman and that he reckoned eight in a Boy 's Band also their colour and magnitude were very unequal and their figures discrepant as may appear in many Pictures of them drawn by the Relatour they would not wash out with simple water but requir'd Soap their duration was also unequal some lasting ten or fifteen days and others longer before they disappear'd And these Crosses were found not onely upon Linen Garments expos'd to the Air but upon some of those belonging to Altars that were kept lock'd up in Chests to which possibly they might have access by the Key-holes or some unheeded chinck To which strange Phaenomena if I had the leisure to add some others that I have met with in Agricola and other approved Authours whose Relations my memory doth not now serve me particularly to cite I presume it would appear yet more probable that Subterraneal Effluvia may now and then be of a very Anomalous nature and produce strange effects and among them variety of Pestiferous ones in the Air. But to add this upon the bye though I fear Physicians will not be able to discover all the subterraneal Bodies whose Effluvia produce or contribute to the Plague yet I do not think it impossible that by diligent observations and trials sagacious Men may discover divers of them and perhaps Antidotes against them And though the business of this Paper be to treat of the Causes not the Remedies of the Plague yet I love Mankind too well to suppress on this occasion an Observation that by God's blessing may in some cases save the lives of many In the late great Plague that swept away so many thousands at London there staid in the City an Ingenious Physician that was bred by the Learned Diemerbroeck whose Book De Peste I prefer to any I have yet read of that Disease This Doctour whose name I am sorry I have forgotten hearing that I was desirous to receive an account of the Plague from some intelligent Eye-witness and having soon after some occasion to pass near the Place in the Countrey where I then resided was pleas'd to give me a visit and a rational account of the main things I desired to know and when I inquired about his method of Cure after he had told me that he had twice had the Plague himself whereof he shewed me some effects he added that after many and various trials he perceiv'd that abundance of his Patients died after the Bubos Carbuncles or Pestilential Tumours appear'd because upon a little refrigeration of the Body by the Air and oftentimes by the very fear that disheartened the Patient the Tumours would suddenly subside and the Pestilential Matter recoiling upon the Vital Parts would quickly dispatch the fatal work Wherefore he bethought himself of a method by means of which he assur'd me he had not lost one Patient of very many he treated if he could but as he usually did by good Alexipharmical and Cordial Remedies enable and excite Nature to expell the peccant Matter into a Tumour for then he presently clapp'd on an appropriated drawing Plaster which would never suffer the Tumour to subside but break it or make it fit for opening and thereby give Nature a convenient vent at which to discharge the matter that oppress'd her This Plaster 't will easily be thought I was desirous to know and he told me 't was a Chymical one and that 't was no other than the Magnes Arsenicalis of Angelus sala whose description because the Book wherein 't is found is in few hands I have here annext If this prove as successfull in other Plagues as it did to those that us'd it in that of London there will be just cause to admire and praise the benignity of Divine Providence which in a poisonous Mineral that probably does oftentimes concur to produce the Plague has laid up a remedy for it Emplastrum attractivum Pestilentiale nostrum ℞ Gummi Sagapeni Ammoniaci Galbani an ℥ iii. Terebinthinae coctae cerae virginis ana ℥ ivss Magnetis Arsenicalis subtiliter pulverisati ℥ ii radic ' Aronis pulverisat ' ℥ i. Gummi depurentur cum aceto scyllitico ad consistentiam Emplastri coquantur postea ponderentur deinde cum rebus aliis fiat Emplastrum lege artis hoc Emplastro Carbunculus obducatur quod paucis horis venenum extrahit Praeparatio Magnetis Arsenicalis antea dicti ℞ Arsenici Chrystallini sulphuris vitri antimonii crudi ana haec tria in mortario ferreo pulverisentur in vase fortissimo vitreo ponantur ad ignem arenae donec vitrum optimè incalcscat praedicta solvantur liquentur instar picis quod observabitur quando filum quoddam immittitur in fundum quod extractum postea instar Terebinthinae trahetur ubi satis coctum erit postea remove vitrum ab igne ubi refrigeratum est rumpe subtiliter pulverisa ad usum serva By
the same motive Philanthropy I am induc'd to add on this occasion that having had some opportunity to oblige an ancient and very experienc'd Physician to whose care was committed a great Pesthouse where the Contagion was so strong that he lost three Physicians that were to be Assistants to him and three Chirurgeons of four that were to be subservient to him I disir'd to learn of him if he counted it not too great a secret what Antidote he us'd to preserve himself from so violent and fatal an Infection This request he readily granted but withall told me that his method would not seem to me worth mentioning if I were one that valu'd Medicines by their Pompousness not their Utility For besides ardent Prayers to God and a very regular Diet his constant Antidote was onely to take every Morning fasting a little Sea-salt dissolv'd in a few spoonfulls of fair Water which he made choice of both because it kept his Body soluble without purging or weakning it and for other Reasons which I must not now stay to set down I know this Medicine may appear a despicable one but yet in my Opinion it ought not to be despis'd after such Experience as I have related has recommended it For I think it desirable that notice be taken of all Remedies that have been found by good Trials not bare Conjectures or uncertain Reports available against the Plague For since Pestilences as we have lately noted are exceeding various in their kinds 't is very possible and not unlikely that their Appropriated Remedies may be so too And therefore I would not easily lay aside every Medicine that this or that Learned Physician may speak slightly of or even may declare that he has found it unsuccessfull against the Plague since the same Medicine may be available in a Pestilence of another kind in which perhaps the Remedies commended by the Physician we speak of will be found inefficacious This Consideration forbids me to pass by what happen'd to me in the great London Plague above-mention'd namely that a very Learned Physician having once recommended to me an Herb little noted in England as a most effectual and experienced Antidote against the Plague I caus'd it to be cultivated in a Garden as I still do every year and when the Pestilence raged most having some of it by me made up with a little Sugar in the form of a fine green Conserve I sent it to two infected Persons who by the Divine Benediction on it both of them recover'd But having made but those two Trials I dare not ground much upon them onely though I usually keep the Plant growing in a Garden partly because both the Taste and Colour one or other of which in most Antidotes is offensive are in this pleasant and partly because some little Experience has invited me to believe the Commendations that I have found given of it against the Bitings of venomous Creatures whereof I remember a notable Instance is recorded by Petrus Spehrerius of a Roman who having with his Staff pierc'd or crush'd a Viper that he took to be dead had so strong a Venom transmitted along the Staff that the insuing Night he had a very great Inflammation in both his Lips to which superven'd an exceeding Ardent Fever and strange Tortures from all which Serianus Pacyonius a noted Physician that was call'd to him free'd him as it were by Miracle by the Juice of Goats-rue or as others call it Galega that grew copiously in that Place It may without disgust be taken somewhat plentifully and so it ought to be in its entire substance as a Salad or else one may give its Conserve its Syrup or which is better its Juice newly express'd 3. It likewise agrees with our Hypothesis that sometimes the Plague ceases or at least very notably abates of its Infectiousness and Malignity in far less time than according to the wonted course of that ravenous Disease Physicians did or rationally could expect For sometimes it may happen that though the Temperature or Intemperateness of the Air continues the same the matter that afforded the Pestiferous Exhalations may be either spent under ground or so alter'd by combination with other subterraneal Bodies or by some of those many Accidents that may happen altogether unknown to us in those deep and dark Recesses And if once the Fountain of these noxious Effluvia be stopt so that those that are in the Air cease to be recruited the Wind and other causes may in a short time dissipate them or at least dilute them with innocent Air so far as to keep the Disease they produc'd from being any thing near so mischievous as before And here I consider that it may several times happen that though the Minerals that emit the hurtfull Expirations remain where they were under ground and be not considerably wasted yet their fatal Effects may not be lasting because the Effluvia were generated by the conflict of two or more of them which vehemently agitated one another and sent up fumes which ceas'd to ascend at least in great plenty when the Conflict and Agitation ceas'd As I have try'd that by putting good Spirit of Salt upon Filings of Steel or Iron in a conveniently shap'd Glass there will be made a great conflict between them and without the help of external Heat there will be sent up into the Air store of visible Fumes of a very Sulphureous Odour and easily inflammable which copious elevation of Fumes will lessen or cease as does the tumultuous agitation that produc'd them And so likewise if you pour Aqua fortis upon a convenient proportion of Salt of Tartar there will be at first a great ebullition produc'd and whilst that continues store of red and noisome Fumes will be elevated but will not long outlast the commotion of the mixture whose active parts will in no long time combine into a kind of nitrous Salt wherein the noxious parts of the Menstruum are as it were pinion'd and hinder'd from evaporating or ascending though really they retain much of their pristine nature as I elsewhere shew It may also happen that soon after that commotion of subterraneal Matter which sent forth pestiferous Exhalations a more intense degree of subterraneal Heat or perhaps the same latent Fire extending it self farther and farther may force up Fumes of another sort that being of a contrary nature may be if I may so speak antidotal against the former and by precipitating them or combining with them may disable them from acting so mischievously as otherwise they would To countenance which I shall tell you that I have sometimes purposely made Distillations in which one part of the Matter being after the operation ended put to the other there will ensue a sudden and manifest conflict between them and sometimes an intense degree of Heat And that mineral Exhalations though otherwise not wholesome may disable pestiferous Effluvia may be gather'd from what I lately noted about a
fusible nature needing no other and though it were removed but very little from the fire it was so disposed to shrink upon a small degree of Refrigeration or rather abatement of Heat that before it was sensibly cold it would crack with a noise in so vehement a manner that notwithstanding the ponderousness of the matter which had been purposely laid upon a Levell parts of a considerable bulk weighing perhaps some Drams would fly to a not inconsiderable distance from one another And this Experiment I took pleasure to make more than once And if you will be content with an Instance which though otherwise much inferiour may not be unwelcome for its being easily and readily made I shall offer you one that I have often repeated Take a piece of Copper if the Plate be thick 't is so much the better and having throughly brought it to a red or white Heat among kindled Coals take it from the fire and when it begins to cool a little hold it over a sheet or two of white Paper and you will perceive good store of flakes to fly off not without some little noise one after the other and sometimes perhaps as far as the farthermost edges of the paper which flakes or scales seem by their brittleness and colour to be but parts of the surface of the metal vitrified by the vehement action of the fire and afterwards by a too hasty refrigeration shrinking so violently as to crack and leap from one another like the contiguous parts of the string of a Viol or other Musical Instrument that breaks by the moisture of the Air. And on this occasion I shall add that having afterwards inquired of an expert Artificer that made metalline Concaves about the shrinking of his mixtures of metalls he confessed to me that he usually observed them to shrink upon Refrigeration And the like I my self have observed in Iron of a great thickness and purposely fitted to a hollow body of metall which it would not enter when it was ignited though it would when 't was cold But to shew you by a notable Instance or two both that Metals may shrink and that they may doe so with a very considerable force I shall add that I found by inquiry that the lately mentioned Artificer after he had made some large Concaves of an unfit mixture of metals and having removed them from the fire had been very carefull to keep the cold Air from them lest they should cool too hastily observed yet to his great loss that when they came to be further refrigerated they would perhaps after three hours crack with a great noise though this metalline mixture were perchance harder than Iron and three or four times as thick as common Looking-glasses But the misfortune of another Tradesman afforded me a yet more considerable Phaenomenon For this excellent Artificer whom I often employ and with whom I was a while since discoursing of these matters complain'd to me that having lately cast a kind of Bell-metall upon a very strong solid Instrument of Iron of a considerable superficial Area though the metal were suffer'd in a warm room to cool from about eight a clock on Saturday night till about ten or twelve on Monday morning and were then which is to be noted considerably hot to the touch yet it cool'd so far that shrinking from the Iron that would not shrink with it the Bell-metall cracked in divers places with noises loud as the Report of a Pistoll though the metall he affirm'd to me was an inch and half or two inches thick And the same person shewed me a large Cylinder of Iron about which for a certain purpose a Coat of Bell-metall had been cast some days before on which Bell-metall there was a crack near one end made by the coldness of the Iron though the thickness of the Bell-metall as near as I could measure it exceeded an inch and as the Workman affirmed an inch and a quarter Nor is it onely in such mixtures as Bell-metall which though very hard may be very brittle but even in a metal that is malleable when cold that the like Phaenomenon may be met with as I have been assured by another ingenious Artificer of whom I inquired whether he had taken notice of the shrinking of metalls who affirm'd to me that having had occasion to cast about a Cylinder of Iron a ring or hoop of Brass he found to his trouble that when the metall began to cool the parts shrunk from one another so as to leave a gaping crack which he was fain to fill up with soulder quite crosse the breadth of the ring though this were above an inch thick I should not Pyrophilus have in this Chapter entertained you with more Experiments of others than of my own if I had the conveniency of living near Founders of metalls as the Tradesmen had whose Observations I have rectied and whose sincerity in them I had no cause to question And both their Experiments and mine seem to teach that a body may be brought into a state of Tension as well by being expanded and stretch'd by the action of the fire upon the minute parts as by the action of an external Agent upon the intire body And to speak more generally the state of violent Contraction and Compression may not unfitly be illustrated by a Bow that is bent For as the Bow it self is brought to a state of Compression by the force of the Archer that bent it so by the Elastical force of the bent Bow the string is brought into a violent state of Tension as may be made evident by the cutting off the string in the middle for then both the Bow will fly suddenly outwards and the parts of the string will swiftly and violently shrink from one another And according to this Doctrine the effect of other bodies upon such as are thus brought into what men call a Preternatural state is not to be judg'd barely according to usual measures but with respect to this latent Disposition of the Patient as for instance though the string of a Viol not screwed up will not be hardned by the vapours that imbue the Air in moist weather yet a neighbouring string of the same Instrument though perhaps much stronger being screw'd up and thereby stretched will be so affected with those vapours as to break with noise and violence And so when one part of a piece of Glass is made as hot as can be without appearing discolour'd to the Eye though a drop or two of cold water have no effect upon the other part of the same Glasse yet if it touch the heated part whose wonted extension as I have elsewhere proved is alter'd by the fire that vehemently agitates the component particles the cracking of the Glass will almost always presently ensue If against these Instances it be alledged that it is possible to assign another cause of the seemingly spontaneous breaking of the bodies mention'd in this Chapter than that which
Essay taken notice of But perhaps it may be worth while to enquire what kinds there are of it and what effects they may have in the parts of Solid bodies themselves For I have observed that though those Stones that the Italian Glass-men use are very hard and if I misremember not have several times afforded me sparks of fire by Collision yet by rubbing them a little one against another I found that such an agitation was made in their parts as to make them throw out store of foetid exhalations And 't is possibly to the stony Ingredient that Glass owes the Quality I have observed in it and elsewhere mentioned of emitting offensive steams And 't is remarkable to our present purpose that though so vehement an agitation of the parts as is given to Glass by Heat when 't is made almost red-hot in the fire does not make it sensibly emit odours yet barely by dextrously rubbing two solid pieces of Glass against one another one may in a minute of an hour make those fixed bodies emit such copious steams as I found not onely sensibly but rankly foetid though one would think those stinking exhalations very indisposed to be forced off since they were not expelled by the vehement fire that the Glass long endured in the furnace where 't was kept melted There are few things that shew better both how the parts of Inorganical bodies communicate their vibrating motions to one another and how brisk those motions are than that which happens upon the striking of a large Bell with a Clapper or a Hammer For though the stroak be immediately made but upon one part yet the motion thereby produced is propagated to the opposite and the successive vibrations of the small parts do even in so solid and close a body as Bell-metal run many times round as may appear by the durableness of the ringing noise which seems plainly to proceed from the circularly successive vibrations of the parts which unless they briskly tremble themselves can scarcely be conceived to be fitted to give the Air that tremulous motion whose effect on the Ear when the first and loud noise made by the percussion is past we call Ringing And this motion of the parts of the sounding Bell may be further argued by this that if the finger or some other soft body be laid upon it the sound will be checked or deaded and much more if a broad string though of a soft substance be tied about it And not onely an attentive Ear may often make us guess that the ringing sound is produced by a motion propagated circularly in the Bell but this vibrating motion may sometimes be also felt by the tremulous motion communicated by the trembling parts of the Bell to the finger that is warily applied to it That this motion passes in a round from one side of the Bell to the other seems manifest by the great difference of sound especially in regard of ringing that may be observed in a sound Bell and in a crack'd one where yet all the matter and the former figure are preserved onely the intireness or continuity which is necessary to the circulation if I may so call it of the tremulous motion is at the Crack stopt or hindred And that the motion of the parts is very brisk may be guessed partly by what has been said already but much more if that be true which not onely is traditionally reported by many but has been affirmed to me by several Artificers that deal in Bells who averred as an experienced thing That if a conveniently sized Bell were bound about any thing hard with a broad string and then struck with the usual force that it would otherwise bear very well that percussion would break it giving a disorderly check to the brisk motion of the parts of the Bell whereof some happening to be much more and otherwise agitated than others the force of their motion surmounts that of their Cohesion and so produces a Crack But in regard great Bells are not easie to be procured nor to be managed when one has accesse to them I shall add that I took the Bell of a large Watch or very small Clock made of fine Bell-metall which had no handle or other thing put to it save a little Bodkin or skiver of wood whose point we thrust into the hole that is usually left in the middle of the Basis and this sharp piece of wood serving for a handle to keep the Bell steady enough we placed in the cavity of it near the edges for that Circumstance must not be omitted some black mineral Sand or in want of that some small filings of Steel or Copper or some other such minute and solid Powder which yet must not be too small and then striking moderately with the Key against the side of the Bell we observed as we expected that whilst it continued briskly ringing it made many of the filings to dance up and down and sometimes to leap up almost like the drops of Water formerly mentioned to skip when the brim of the Glass was circularly prest by the wetted finger Which prompts me to add that having put a middle-sized drop of water for in this case the quantity is a considerable Circumstance near the lower edge of the Bell 't was easie to make it visibly tremble and be as it were covered over with little waves by a somewhat brisk stroke of the Key on the opposite side And this effect was more conspicuous when a very large drop of water was placed near the edge on the convex side of a hand-Bell whose Clapper was kept from any where touching the inside of it And to obviate their jealousie that not having seen the manner of the above-mentioned motion of the Sand might suspect that 't was produced by the impulse which the Bell as an intire body received from the percussion made by the Key we several times forbare putting-in the filings till after the stroke had been given which satisfied the Spectatours that the dancing and leaping of the minute bodies proceeded from the same drisk vibrations of the small parts of the Bell which at the same time striking also the Air produced a ringing sound which might very well as it did out-last the skipping of the filings the exceedingly minute particles of the Air being much more easily agitable than the comparatively gross and heavy Corpuscles of the Powder And this success our Experiment had in a Bell that little exceeded an inch and half in Diameter And here Pyroph I shall put an end to this Rhapsody of Observations hoping that among so many of them some or other will be able to engage you if not to conclude yet at least to suspect that such Local motions as are wont either to be past-by unobserved or be thought not worth the observing may have a notable operation though not upon the generality of bodies yet upon such as are peculiarly disposed to admit it and so may have a considerable share
in the production of divers difficult Phaenomena of nature that are wont to be referred to less genuine as well as less intelligible Causes FINIS AN Experimental Discourse Of some UNHEEDED CAUSES OF THE Insalubrity and Salubrity OF THE AIR Being a Part of an intended Natural History of AIR LONDON Printed by M. Flesher for Richard Davis Bookseller in Oxford 1685. THE Preface HAving heretofore had occasion to draw together under certain Heads divers unpublish'd Observations and Experiments of my own and some of other men by way of Memorials for a Natural History of the Air I thought fit by more largely treating of two or three of the Subjects distinctly mention'd in my Scheme of Titles to give a Semplar or Specimen of what may be done upon the other Heads of the designed History Vpon this account I treated somewhat largely of the Salubrity and Insalubrity of the Air as a Subject which for the importance of it to Mens healths and lives I thought deserv'd to be attentively consider'd and have its Causes diligently inquir'd into And having observ'd that among the six principal Causes of the healthfulness or insalubrity of the Air namely the Climate the Soil the Situation of the Place the Seasons of the Year the raigning winds and Contingencies whether more or less frequent and especially Subterraneal Steams having I say observ'd that among these Causes there was one viz. the last nam'd about which I thought I could offer something that I had not met with in the Books of Physicians that treat of it I was thereby invited to set down my Thoughts and Observations by way of Conjectures which I was made to believe would appear uncommon and would not prove useless These Observations and Reflexions I referr'd for clearness and distinctions sake to four Propositions But when I had gone thorough the three first and made some progress in the fourth being hinder'd by divers Avocations to make an end of it I laid by the whole Discourse in a place which I thought a safe one but when afterwards I had some opportunity to dispatch what remain'd I found all the diligence I us'd to retrieve the entire Manuscript unsuccessfull At this surprizing Accident I confess I was somewhat troubled because whatever may be thought of the discursive part of those Papers the Historical part contain'd divers matters of Fact that I did not meet with in Books nor can now distinctly remember and will not perhaps be lighted on by even Physicians or such Naturalists as derive their knowledge onely from them 'T is upon this consideration that having afterwards met with many Papers that belong'd to most parts of the unhappy discourse I thought fit to put them together in the best order I could that I might not loose what might give some light to so important a Subject as the Theory of Diseases And this course I the rather pitch'd upon because before the Papers about the Salubrity of the Air I miss'd two other of my Manuscripts whereof the former contain'd a Cellection of Medicinal things and the second a defence of the Mechanical way of Philosophizing about Natural Things as it respects Religion And I remember'd that having formerly lost a Manuscript I was much concern'd for I purposely made a noise of it whence I suppos'd the Plagiary would conclude himself unable to make it pass for his And in effect the Book was in a while after privately brought back so that I found it laid in a By-place where I had before as fruitlesly as carefully sought it AN Experimental Discourse Of some Unheeded CAUSES OF THE Insalubrity and Salubrity OF THE AIR c. THE sixth and last thing upon which the Salubrity and Insalubrity of the Air depends is the impregnation it receives from Subterraneal Effluvia And though this be a cause not wont to be much heeded by Physicians themselves yet I take it to be oftentimes one of the most considerable in its effects The Effluvia that pass into the Air may be distinguish'd into several sorts according to their respective Natures as has been elsewhere shewn wherefore I shall now only take notice of the differences that may be taken from place and time upon which account we may consider that some of them arise from the Crust if I may so call it or more superficial parts of the Earth and others have a deeper Original ascending out of the lower parts and as it were Bowels of the Terraqueous Globe And to this difference taken from place I must add another perhaps no less considerable afforded by Time which difference relates chiefly to the second sort of Steams newly mentioned Of the Subterraneal Effluvia some are almost constantly or daily sent up into the Air and those I therefore call Ordinary Emissions and others ascend into the Air but at times which are not seldom distant enough from one another and those I call Extraordinary Emissions whether they come at stated times and so deserve the title of Periodical or else uncertainly sometimes with far greater sometimes with far smaller intervals and so may be called fortuitous or irregular But though I thought it might render what I am about to say more clear if I made and premised the two foregoing distinctions yet because in many cases Nature does not appear solicitous to observe them but at the same time imbues the Air with Steams referable to divers Members of these distinctions I shall several times though not always take the liberty to imitate her and consider the Effluvia of the Terraqueous Globe in the more general Notion that they are so I know 't is frequently observed and usually granted that Marrish Grounds and wet Soils are wont to be unhealthfull because of the moist and crude vapours that the stagnating waters send up too copiously into the Air. And on the other side dry Soils are because of their being such generally lookt upon as healthy Nor do I deny that these Observations do most commonly hold true but yet I think that besides what can be justly ascribed to the moist vapours or dry Exhalations we have been speaking of in many places the healthfulness and insalubrity of the Air may be ascribed to other sorts of Effluvia from the Soil than those that act merely or perhaps principally as these are either moist or dry PROPOSITION I. TO deliver my Thoughts about this matter somewhat more distinctly I shall lay them down in the four ensuing Observations or Propositions whereof the first shall be this It seems probable that in divers places the Salubrity or Insalubrity of the Air considered in the general may be in good part due to subterraneal Expirations especially to those that I lately call'd Ordinary Emissions For in some places the Air is observ'd to be much more healthy than the manifest qualities of it would make one expect and in divers of these Cases I see no Cause to which such a happy Constitution may more probably be ascrib'd than to friendly Effluvia