ERRATA.  
PAge 6. for omitted, r. emitted, p. 14. l. 9 of left out.   

ADVERTISEMENT.  
Books Published by the Honourable Robert boil, and Printed for John Tailor at the Ship in St. Paul's Churchyard.  
1. A Free Inquiry into the Vulgarly received Notion of Nature, made in an Essay addressed to a Friend: In English and Latin.  
2. The Martyrdom of Theodora and Dydimus.  
3. A Disquisition about the final Causes of Natural things; wherein it is enquired, Whether, and (if at all) with what Cautions a Naturalist should admit them? To which are subjoined, by way of Appendix, some uncommon Observations about Vitiated Sight.  
4. The Christian Virtuoso: Showing that by being addicted to Experimental Philosophy, a Man is rather assisted, than Indisposed to be a good Christian; to which are subjoined: 1st. A Discourse about the Distinction that represents some things as above Reason, but not contrary to Reason. 2. The first Chapters of a Discourse, Entitled Greatness of Mind Promoted by Christianity. Printed for J. Taylor at the Ship; and J. Wyatt at the Rose in St. Paul's Churchyard.   

Experimenta & Observationes PHYSICAE: Wherein are briefly Treated of SEVERAL SUBJECTS Relating to Natural Philosophy IN AN EXPERIMENTAL WAY.  
To which is added, A small Collection of STRANGE REPORTS.  
By the Honourable ROBERT boil, Fellow of the Royal Society.  
LONDON, Printed for john Tailor at the Ship, and john Wyatt at the Rose in S. Paul's Churchyard. MDCXCI.   

A Letter that may serve for a Preamble.  
To my Learned Friend Mr. H. Oldenburg (Secretary to the Royal Society.)  
SIR,  
BEing at length come to a Resolution, I have already done something more than barely entered upon that way of Writing, that you and I have more than once Discoursed of together; and wherein you particularly (though not you only) among my Learned Friends, have wished to see me Engaged.  
'Tis not, that I am insensible of the Prejudice which the things I deliver are like to sustain, by the disadvantageous Dress wherein they must appear, in the way of Writing I have pitched upon; which being for the most part plainly Historical, and set down in the order wherein, they chanced to come to hand, denies most of them, not only the usual Ornaments of other Books, but the allowable Advantages, that Method, elaborate Discourses, neat Hypotheses, and subtle Disputes, are permitted to bring even to Philosophical Writings.  
But these Considerations were overswayed by a sad one, founded upon the (yet continuing) condition I was in, when I was Debating this matter in my Thoughts. For it having pleased God (to whose always most just Dispensations Men ought entirely to submit) to Afflict me with the Stone and the Palsy; as on one side, these, added to a sufficient number of Avocations, scarce permit me any great expectation, of finishing in a short time the Tracts I had made a lesser or greater Progress in, according to my first design; so on the other side, my Friends judging it unfit, that the Materials provided for these more than begun Treatises, should be quite lost, or kept too long useless, it seemed expedient, that as Opportunity should from time to time serve, I should look over my Memorials, and other scattered Papers, to take notice what Experiments and Observations were to be found in them.  
Upon these, and the like inducements, having picked up several of my dispersed Papers, some of them Written many Years ago, and some of a less ancient date; I began to refer the most part of what I found Historical in them, together with some few things that did seem necessary not to be severed from them, to certain Heads or Titles which I called Chapters; and made them the more numerous, that they might singly be the less Prolix: And about these I must desire your leave to represent some things, by way of Preface.  
And first, several of the ensuing Particulars that I met with among my Papers, being parts of Essays of other Discourses, and being for haste Transcribed for the most part Verbatim, as they were couched there; I dare hope for your excuse, if among such Transcripts you now and then meet with things, which, how pertinent soever to the Tracts they first belonged to, might have been spared as needless, if not sometimes Foreign; also, in the new Form the Discourses are now put into; since I could not leave out such unnecessary Clauses (whereof yet I hope you will not find many) without too much mutilating the coherence, or obscuring the sense of what is delivered; and I could not alter them, and adapt others to supply their places without spending more time, and taking more Pains, than in the condition I am now in, I suppose you would be willing to condemn me to.  
Next, I despair not but you will allow me the Liberty I have taken, to vary the Bulk and Method of particular Chapters, as my occasions would permit, or the plenty or paucity of Materials suggested; or the Nature of the thing I treated of, and the Scope I proposed to myself in Writing of it, seemed to require. But sometimes my want of Health and Leisure, and my desire to hasten to other subjects, that either pleased me better, or seemed more considerable, made some of the following Chapters, compared with others, but short; especially, if I were supplied but with a number of things pertinent to that Subject, by the Papers I had then in hand, how much soever I may have Written of it in other Papers, which I hope hereafter to be Master of.  
And this Advertisement may render you a Reason why to the Title of some of the Chapters I have subjoined the first Section, though it be not at present followed with a second.  
And, as for my having employed very differing Methods in some of the ensuing. Tracts, I did it with design, as judging such a variety of Method more conducive to my purpose, than Uniformity in it would have been. For, besides that some of the Treatises, uhence these Chapters were taken, did, by the ways wherein they were already Written, oblige me, to accommodate myself to their Method; I thought, that if you should show these Papers to any, that are very unacquainted (which I have heard you complain, that too many are) with the way of accommodating in some tolerable manner, his Inquiries and his Writings to the several Subjects he applies himself to, he may be somewhat helped, by the differing Examples he may here meet with, to make variations somewhat suitable to the differing Natures of the Subjects he deals with.  
But here I must beg you to take notice, That, though in compliance with this design, as well as for some other reasons, I have in several of the following Chapters given intimations and hints of things, which I do not there prosecute; and now and then propose some Conjectures and Opinions, whose proof I do not insist on; yet I am not willing you should think, that, however some of those passages may be but occasional things, mentioned principally to excite, and give hints to the inquisitive and sagacious; yet all, or most of them, are of the same kind; and that I thought not on them, but as slightly and transiently as I mentioned them; and have no better and other Reasons to allege for my suspicions or intimations, or even for my conjectures or my opinions, than those you will meet with in Papers hastily drawn up; especially since, I think, I can show you divers of the things delivered in those passages, enlarged and rendered at least probable or practicable in other Discourses, that for certain Reasons do not accompany these I now send you.  
I expect, that you should think it somewhat strange, to find many of the following Experiments set down much less circumstantially than those that are mentioned in the Physicomechanical Experiments touching the Air; in the Continuation of them; in the History of Cold, and in some other Books of Mine that you have been pleased to peruse. But on this occasion give me leave to represent to you, that the nature of divers of the former Experiments, especially Chemical ones, and my aims in mentioning them, being considered, it seemed not requisite they should be more fully Treated of: And as for others, though the brevity and dispatch; which divers reasons made me propose to myself, had not forbidden me to amplify; yet I daily feel my leisure, not to say my Life too; so torn piece●●●● from me, by Sickness, Visits, Business, and inevitable Avocations, that I am frequently admonished to hasten the securing of as much as conveniently I can, by dispatching particular Subjects, and am quite hundred from dwelling so long upon them, as, if I had more Health and Leisure, I should willingly do. To these things perhaps, so favourable a Person as Mr. Oldenburg will add, that the Characters which Learned Writers, English and Foreign, though divers of them personally unknown to me, have been pleased to give of the diligence and sincerity employed in setting down the Physicomechanical Experiments, and those of some other Writings of Mine, may permit me to hope, that it will be thought, that, after having been divers years versed in making Trials and Experiments, I have made them with some care and wariness, and mentioned them faithfully, where I have not done it amply; upon hopes it may be taken in good part from a Person in my present condition, that was never a Professor of Philosophy, nor so much as a Gown-man; to have made shift to make the Experiments and Observations he communicates, and set them down truly and candidly, without fraudulently concealing any part of them, for fear they should make against him. And though perhaps you will easily believe, that in divers of the Experiments which I have but briefly mentioned, I have been as diligent an Observer of Circumstances, as I was wont to be when I made those, which have had the luck to be taken notice of for being fully related; and though it may be also, that some Scruples or Objections, which my brevity may in part occasion, were not unforeseen by me, and might have been avoided by a more copious and diffused way of Writing; yet I purposely decline such a way of delivering things, not only for the reasons above mentioned; and because I suppose them that may peruse these Papers, to be acquainted with my formerly Published Writings, and to have either from them, or otherwise, understood the way of making such Experiments as mine; but also, because, though I wanted Time and Health, much less than I do, I should not think it fit too much to prevent the Industry of others about the Trials I mention; and reap the Field so clean, as not to leave them, not only store of Ears to Glean, but some corners of standing Corn. I have therefore here and there purposely omitted, both, some not absolutely necessary Practical Directions about making of Trials, that might prevent such Scruples or Objections, as have the Grounds of answering them clearly delivered in my Printed Books; and several, not only lesser Circumstances, but considerable Phaenomena, and obvious Applications, that may probably occur to others, as they did to me in making the Trials and Reflecting on them.   

Advertisements about the Disposition of the following Treatise.  
YOU will quickly discern that the following Chapters could not be intended for complete Tracts, about the Subjects handled in them. And indeed they were intended but for such Memoirs about the Various particular Subjects they Treat of, as may be serviceable to the Solid Natural History that has been nobly designed and is still prosecuted, by the Royal Society. Wherefore since (at least in our Age) no Writer that I know of, has so early and so well, both urged the necessity of Natural History, and promoted divers Parts of it by Precepts and Specimens', as the illustrious Lord Verulam; I shall not scruple in the way or manner of Writing these short Collections of mine, to make use somewhat frequently of his Authority and Examples; but without Confining myself to either.  
I. Agreeably to this Advertisement you will find, that some of the Particulars that the following Treatise consists of, are single and as it were, Independent ones; upon which account they resemble those which in the Verulamian Sylva, or Natural History, are called Experiments Solitary: And have for that reason induced me to give that Title to each of the several Chapters that are made up of them.  
II. Another sort of Chapters there is, wherein divers Experiments and Observations, all of them relating to the same Subject or Purpose, are set down together. These if they were ranged and sorted in order to distinct Theories, I should call, in imitation of the mentioned Author, Experiments in Consort. But my backwardness to frame Theories has made me choose to forbear as yet to methodise them, and therefore has made me think fit to call them only various Experiments and Observations about this or that Subject (which they belong to.)  
III. My haste, though not that only, induced me to make one sort of Chapters more, that partly agrees with, and partly differs from each of the two that I come from mentioning: For in every one of these Chapters, there are two or three, if not more, single or Solitary Experiments; and there are also others that have some kind of Connexion among themselves, as being referable to the same Subject or Purpose. On that score the Title that is given to each of the Chapters of this Third sort, is that of Miscellaneous Experiments; and sometimes (but seldomer) of Promiscuous Ones. And all the Particulars that I refer to the three forementioned Heads, are cast into Chapters, wherein the several kinds are distinguished only by their Titles, or not.  
IV. There is one Advertisement that regards all the sorts of Particulars that are referred to the foremention'd Chapters, which is, that I have usually comprehended Observations, as well as Trials, nuder the Title of Experiments; which I have done, not only upon the Authority, and in following the Example of our Judicious Chancellor (as is every where obvious in his Sylva Sylvarum) but for other reasons too. For both the sorts of Particulars may pass for matters of Fact, and so are Historical, taking the word in a lax sense, and the employing it in that sense, makes the Articles or Passages, whereof the Chapters and other parts of our Collection consists, much more commodious for References and Citations.  
V. Besides the three forementioned kinds of Chapters, you will meet in the ensuing Treatise with another sort of Writings, whereof some are almost entire, and others Fragments of larger Discourses. In neither of these, I did confine myself so much to matters of Fact, as in those Chapters that consist of Experiments and Observations; but took the liberty, as occasion required, to enlarge in Discourses, and sometimes to Cite such passages out of other men's Writings, as I judged I could make some pertinent Application or use of, perhaps unthought of by the Author. And these Papers being most, if not all of them Written in a more free and discursive way, I thought fit to separate them from the Sets of Collections that are almost merely Historical; and accordingly I have not styled them Chapters, but Titles; and have forborn to assign them, as I did the others, Ordinal Numbers; which I desire likewise you would not prefix to any of them, because I am not yet resolved how I shall dispose of them, either by supplying what is wanting to finish any one, or more of them, or by taking to pieces, and employing those pieces as Materials for other Tracts.  
VI Perhaps I shall not be thought to need Pardon, if to comply with their Curiosity, who affect most those Experiments, that are either uncommon, or teach them to do or perform something useful or pretty; I sometimes prefix a Title declaring what it treats of, to a particular Experiment (or Observation,) which for its Importance, Novelty, or usefulness (Theorical or Practical) may deserve to bedistinguished; since by this means such Particulars may be the better impressed on the memory, to gratify those, whose nicety or want of leisure, may make them well pleased by a transient view of the Titles we speak of, to find such Passages as they chiefly looked for, with less trouble than that of perusing an Index.  
VII. Among the Experiments our Collection consists of, there is here and there one, to which it was thought fit to add something, either by way of Explication, or of Illustration, or of Confirmation, or of Answer to Objections, or of Theorical Reflection, or of Practical Application, etc. And these Supplements or Additions it was thought fit to call sometimes Annotations, but oftener Scholiums', because that Term is freely used in a very comprehensive Sense by Mathematical Writers. But though I readily acknowledge that this Term has been chiefly employed by Mathematicians, yet the use of it has not been so confined to them, but that good Authors in other parts of Learning have not scrupled to employ it, as may appear by the Scholiums' that some Learned Physicians have Written upon Hollerius, an eminent Person of their Profession; as also by the Example of the famous and Experienced Forestus, who has not seldom subjoined Scholiums', even to his own Medicinal Observations.  
VIII. The mention of these Scholia prompts me to tell you, I had almost forgotten, but yet must not leave unmentioned, that I thought fit now and then to premise to Sets of Experiments, and sometimes (though more seldom) to a single Observation a short Preamble by way of Introduction, which may often excuse the need of subjoyning a Scholium; and may be warranted by the Example of the Lord Verulam in his Centuries, wherein he often inserts such short Preambles, as things fitted to give light to the Experiments they belong to, and to give some Advertisement both of the Nature and Importance of the Subject, and of the Scope of the Writer, or of other useful circumstances.  
IX. If among my own Experiments, namely, those that I have made or seen, I have sometimes inserted Experiments or Observations that are not so: I have not done it without reason, and am authorised in that Practice, by frequent Examples afforded me by the first, if not only Author that I know of, that gave us a Set of Precepts of well writing Natural History, our often cited Verulam, whose Centuries do in great part consist of borrowed Experiments and Observations; without which, he was sensible that his Sylva must be of too narrow a compass, or too thinly stocked with Plants, especially with Trees. And indeed 'tis not to be expected, that, as the Silkworm draws her whole Mansion altogether out of her own Bowels, so a single man should be able to write a Natural History out of his own Experiments and Thoughts. And he that will strictly confine himself to those, will be often reduced to omit things very pertinent, if not necessary, to his Subject, which is of practice studiously declined by me, who prefer the Readers Utility, to the ambitioned Glory of being thought to borrow nothing from any Body. And I can add in my Defence, at least my Excuse, that I have made use but of a small part of the Liberty allowed me by the Example of so great a Guide in the way of Writing Natural History. For I have very much seldomer than he, employed the Trials of others; and have yet seldomer mentioned unverified Reports or vulgar Traditions, being careful that the Bulk of the Matters of Fact I deliver, should consist of things, whereof I was myself an Actor, or an Eye witness; and that the comparatively few borrowed Experiments that I added, (that I might not deprive my Reader of some things very pertinent and useful to my Subject) were received from Persons of very good credit; besides that I do not only frequently give sufficient Intimation in the Experiment or Observation its self, but oftentimes by placing the Letter C in the Margin, do give notice; nay, and sometimes to a whole Set, prefix the Title of Communicated Experiments or Observations.  
X. I have nothing more to give you notice of here, save that, whereas you will find that I Write but on one side of the Leaves, whereof this Book 
* This refers to the Manuscript that was sent to Mr. O. and is left to show the Intention of the Author.  consists: I did so for two Reasons. The First, That in case I should have occasion to employ any of these Experiments in other Treatises, for which I am more concerned than for this Rhapsody, I might have room to Substitute, if it should be thought fit, one or more of my later Experiments in its place. And Secondly, That I might have room, if I can get leisure, to Write Annotations, or make Reflections, or Illustrations, or Corrections, or in a word, such Addititions and Alterations of particular Experiments and Passages, as they shall be thought to deserve or need.  
I am sensible that this Preamble, increased by the Advertisements that 'twas thought necessary to annex to it, is of a length that may seem disproportionate to the Book or Tract 'tis prefixed to. But I may in excuse of this represent to you, that the Bundle of Writings you now receive, is but a part of the Book; to which, if God vouchsafe me Health and Leisure, this Preface enlarged by its Appendix, is designed for an Introduction. And in that case 'tis hoped that these Preliminaries, as many as they are, will not be thought Impertinent, or needlessly prolix.   

Experimenta & Observationes PHYSICAE. TOME I.  

CHAP. I.  
CONTAINING Chymico-Magnetical Experiments and Observations.  
THE Loadstone, Pyrophilus, is so admirable a Body, and its Usefulness to Mankind is already so great, without denying us hopes of farther Improuments; that I think we must want Curiosity or Gratitude, if we neglect either to take notice of any Experienced Phoenomena that directly relate to so abstruse a Subject, or, by consigning them to Paper, to preserve them from Oblivion. 'Tis chiefly by this Consideration, Pyrophilus, that I am induced to mention to you the following Experiments and Observations, made most of them by the help of the Fire. For, though some of them may seem but slight; yet they may not prove unuseful, towards discovering the Nature of a Body so strange and singular, that, for aught is yet manifest, any true Magnetical Phoenomena may somewhat conduce to the knowledge of it, And I was the rather induced to make Trials and Observations of this Kind, because most of them are such as I have not met with in Authors. And the few that remain, I have not found sufficiently taken notice of there; Philosophers and Mathematicians aiming chiefly, in their Magnetical Writings, to prosecute and apply the Attractive and Directive, and perhaps the Inclinatory, faculty of the Loadstone. Whereas, throwing into another Paper, what I Observed, of that kind, I did in the present Inquiry mainly intend to make the Loadstone rather the Object than the Instrument of my Trials: and handling chiefly the very Substance of the Stone, endeavour not so much to Advance or Apply its Faculties, as to Weaken and Destroy them, though in order to the better knowing of them. Having therefore procured a considerable number of, for the most part naked (or uncapt) Lodestones, most of them Course, but of differing Sizes, Shapes, Colours, and Countries; I made upon them several Trials, some of which I should immediately proceed to give you a brief Account of, but that 'twill be proper to premise this short Advertisement: That, I would not have the Title of these Experiments make you expect, that the Fire should be a main Agent in every one of them, since to preserve some few of them, I refer them hither, though an actual Fire was not Employed to make them: Since the common Rule that a potiori parte fit denominatio, will suffice to Warrant, or at least excuse, my giving to this small Collection the Title of Chymico-Magnetical Experiments; because the greatest part were performed by the help of the Fire, or Bodies Chemically prepared by the Application of it. And because 'tis usual with the best Writers about Magnetism, to reckon Steel and Iron among Magnetical Bodies; I shall not scruple to deliver in this Paper some Experiments, made by the help of the Fire upon those Subjects; with reference neverthe less to Magnetism.  

EXPERIMENT I.  
Having Ignited several Lodestones, and removed them from the Fire till they grew Cold again, I found a great disparity in the visible substance whereof they consisted, and the manifest structure of the gross parts that made them up. For some Stones upon Refrigeration, either fell asunder of themselves, or grew very Brittle; when as others still continued in their entireness: Some of them being broken looked not unlike Iron-Ore, or Stones which I have gathered near Iron-Mynes in Kent; others being broken, after Refrigeration appeared to consist of Plates or Flakes of several Colours, and lying Parallel to one another: And others again, which as I remember were English ones, did neither appear to be composed of any such Flakes, nor had their dark Colours much, if at all changed by the operation of the Fire, nor did cease to be Solid Bodies.   

EXPERIMENT II.  
We could not upon the Burning of several small Lodestones one after another, discern any such blue sulphureous Flame as Porta in his 
Lib. 7. Cap. 7.  Natural Magic relates himself to have seen, and judges to have been as it were the Soul of the Loadstone, upon whose recess he says, it lost its Magnetic Faculty, which is most commonly true as to any considerable degree of the Coitive or Attractive Power, but not of the Directive Faculty or Virtue. But it may be that Porta mistook the small Flame, which is often omitted even by well-kindled and glowing Charcoals, (on which sort his Loadstone was placed) especially when a little blown upon, for the exhaling Soul of the Loadstone; or else, to be civil to him, we may suppose, that, His Stone was more rich in Unctuous Moisture than Others are wont to be; and if we had had by us a very exact pair of Scales, we should have endeavoured to have by them discovered, 
See Exper. 10.  whether the Fire do deprive Lodestones of any ponderable parts.   

EXPERIMENT III.  
The Solidity of some English Lodestones, made me think it fit, though I looked upon them as a kind of Iron-Ore, to try whether they could not be brought to strike Fire. And accordingly, having made divers Collisions betwixt a rough piece, and the steel of a Tinder Box; I found that with much ado it was possible to obtain some Sparks, (though they seemed but small ones:) But having taken a large piece of smooth Loadstone, I found that, by striking it somewhat briskly, with the edge of a steeled Hammer, we were able to produce good store of Sparks, and some of them of a surprising bigness; for they were judged to exceed the size of those that are usually afforded by common Flints.   

EXPERIMENT IU.  
For certain Reasons I thought fit to make a further Trial, being desirous to satisfy myself, whether it were not possible, to make Lodestones afford Fire without the help of Iron or Steel. And being willing to comply with this Curiosity, I made choice of two solid pieces of Loadstone, that were cut almost into the form of Cubes; and found that many Collisions being made between them, especially at the edges; there were produced from Time to Time, (though not frequently,) some Sparks of Fire, though neither so numerous, nor so great or vivid, as those of the foregoing Experiment wherein the Steel was employed.   

EXPERIMENT V.  
I have (elsewhere) formerly related, that if an Oblong Loadstone made glowing hot, be refrigerated Perpendicularly, the lower extreme will thereby become its Northern Pole. And I shall now add, that yet if such a Loadstone be refrigerated Perpendicularly, not upon an ordinary Terrestrial Body, but upon the Northern extreme of a much stronger Loadstone; in such case, this debilitated Stone will receive its Impressions, as if it were an Iron, and its lower extreme will not be, as before, by the Magnetic Effluvia of the Earth, made its Northern Pole; but it will be chose animated by the Pole of the Loadstone, on which 'tis cooled; and according to the Laws Magnetical, the lower extreme of it, will not be its Northern, but its Southern Pole, nimbly attracting the North end of an excited and Aequilibrated Needle.   

EXPERIMENT VI.  
By the forementioned way of Refrigeration I also found, that a Disanimated Loadstone (if I may so speak) may be restored, to some degree of its Attractive Virtue; for I tried that a small Loadstone, which after its being made red hot in the Fire, and cooled Perpendicularly upon the Ground, was not able to take up a fragment of a Needle; being again heated, and not only cooled upon the Pole of a strong Loadstone, but suffered to rest on it a while after, was soon grown vigorous enough, to take up what formerly it could not move.   

EXPERIMENT VII.  
I further observed, that though a Loadstone that had passed the Fire, had not, by being immediately before made red hot, had its Body opened and fitted to take in plentifully the Magnetical Streams; yet it would, like a wire of Iron, acquire a new Verticity from the vigorous Loadstone; but not be in many Hours so vigorously impregnated with Magnetic virtue, if it were applied cold to the Pole of the Animating Loadstone; as it would in a very short time, if being glowing hot it were refrigerated thereupon.  
N. B. It has been observed, that if a Loadstone be made red hot in the Fire, it will scarce retain any sensible Attractive virtue, save that it will be able, by being endowed with a Magnetism from the Earth, to drive away that Pole of a Needle well poised, which agrees in Denomination with that Pole of the Loadstone, which is applied to it. But I desire that it may be remembered, that I intimated that this is not strictly and universally true; for in some of our English Lodestones, it has been observed, that Ignition does not only leave them capable of a Directive Virtue, but leaves them also a considerable Attractive power, so that they will sustain a good weight of Steel (as will appear hereafter.)   

EXPERIMENT VIII.  
We took three English Lodestones that appeared to be of a very compact Substance; two of them very small, as not being of near half an Inch in length; the other much greater, being about an Inch long, and of a considerable breadth, but yet of small thickness: These we made red hot in a Fire of well kindled Charcoal, and being thoroughly Ignited, removed them one after another, and hastily set each of them upon a Plate of Silver (for neither Wood nor Iron would have been convenient) and applying the Loadstone (Capped) to each of them, whilst it was yet red hot; it seemed manifest enough, not only, that whilst it was in that state, the Stone had not so strong an Operation on it, as if it were not red hot: But, which is remarkable, when it ceased to appear Ignited, but yet was intensely hot, (so that it was readily able to burn his Fingers that should offer to take it up between them) the armed Loadstone had a more powerful Operation on it, by way of what they call Attraction and Sustentation (not only, as I said, than it had, whilst the Ignited Stone conspicuously retained the colour Fire, but) than it had, after the same Stone was grown cold.   

EXPERIMENT IX.  
This Experiment was reiterated with the two smaller Magnets and the greater, with the like success: And when the Magnets were grown cold, they did notwithstanding their having been twice ignited, discover some little Magnetism, if applied to the end of a well-excited Magnetic Needle, nicely poised upon the point of an ordinary Needle [or brass Pin] (on which its Centre of Gravity leaned.) And I found that the bigger of the three forementioned Lodestones, after the first, if not also after the second Ignition; did not only move the Magnetic Needle more briskly than one would have expected, but, (which may seem strange) being thrust into filings of Mars, and then taken out, it carried up with it and sustained a considerable Number of them. Whence we may conclude, that in some Lodestones of a very solid Constitution, such as this was; the Magnetical virtue is more Radicated (if I may so speak) or Permanent, than in the generality of other Magneticks: This Stone being the first wherein I observed, after I had thoroughly Ignited it, any Attractive virtue able to take up Filings of Iron.   

EXPERIMENT X.  
On occasion of these Trials I made another, which though to some it may seem but slight, I thought the more worthy to be made, because I remember not to have read or heard of it before; we took then, the same Loadstone that we employed about the last Experiment, and having again made it red hot, in the Fire, suffered it not to cool leisurely in the Air, as before, but quenched it, in a Basin of cold Water; intending thereby to make a double variation of the Experiment, first, by cooling it Hastily, and as it were Abruptly; and next by cooling it not in the Air, but in a Fluid some hundreds of times more Dense or Ponderous than the Air. The Event of the Trial was, that, upon the Immersion of the red hot Stone, there fell off some flaky matter, as if it had been Scales of Mars; and the Stone, when cold, would not take up any filings of Iron, as before it did many; so that it appeared to have lost much of the Virtue it so lately had, though it retained the Power to move a well-poysed Needle, if it were held near to either side of the point of it.   

EXPERIMENT XI.  
A black Oblong Loadstone, of a Homogeneous Substance, and weighing near three Drams, having been in a Fire of well-kindled Charcoals, Ignited, and continued so for some Minutes, of an Hour; being weighed again as soon as it was cooled, was found to have lost about ⅝ of a Grain of its first Weight, and much of the blackness of its Colour.  
Tho the Affinity between the Loadstone and Iron, might make one expect that the Fire might have a like Operation upon this Stone, and that out of which Iron is commonly melted, both being indeed Iron-Oars; yet for some Reasons that I cannot now stay to mention, I was induced to think, that the Effect of Ignition upon those two Bodies might be very differing, as I conceive their Internal and unseen Texture to be. And therefore I made the following Experiment.  
A Lump of Iron Oar, which looked almost like a white Stone, rather than a common Oar, and was about the bigness of two Eggs; being applied, in several of its parts, to an excited Needle, did not appear to move it manifestly. But being afterwards made glowing Hot, and kept so for a while, and then Refrigerated; it did in those parts, which seemed by their newly acquired Colour to abound with Metalline Corpuscles; it did, I say, manifestly Attract the North end of the Needle. And this was tried, both with a Needle of our own touching, and by the Mariner's Needle of a Sun-Dyal; whose Flower-de-Luce, the burnt Oar did manifestly draw.   

EXPERIMENT XII.  
To confirm the former Observation, and also what I elsewhere gave notice of, That divers Bodies are of a Magnetical Nature or have in them some parts that are so, which yet are not vulgarly believed to be referable to that sort of Bodies; I shall subjoin the following Experiment.  
A Brick that had not been used, was sawed long ways into two equal pieces, and each of these (one at one time, and another at another) was heated red hot in the Fire for a pretty while, and afterwards suffered to cool North and South: And, as I expected, it thereby acquired a Magnetical Verticity; and with that end that in cooling respected the South, did a little, though but faintly, draw the Flower de Luce (which pointed out the North) of the Mariner's Needle; and with the other end, did somewhat more vigorously drive the Flower de Luce away, and a little attract the other Extreme of the Needle.   

EXPERIMENT XIII.  
We took a [black] Loadstone, and having by degrees beaten it small, without suffering it to touch any Iron or Steel Vesiel or Instrument, [which because of the hardness of the Stone, was very troublesome to do;] we set aside the grosser Grains for other uses, and upon some of the finer Powder we poured the Spirit of common Salt, which had at first a sensible Operation upon it, by producing foetid Fumes, and making a kind of Ebullition, as that Menstruun is wont to do upon filings of Iron or Steel. But nevertheless, being kept a Night or two in Digestion, it drew a high Tincture; and though this was not at all, like the Solutions of Mars in Spirit of Salt, Green, but of a Yellowish Brown, not very remote from Redness: Yet a little of it being dropped into a fresh and sufficiently coloured Infusion of Galls, turned it presently into an Inky Substance, which in some Positions appeared bluish, as a Tincture or light Solution of Mars would have done.. I shall only add, about the Solution of Loadstone, that having carefully made it with a good Aqua regia, obtained a Solution, some of which you may yet command a sight of, that by some Virtuosos to whom I showed it, was thought either a fine Solution of Gold, or little, if at all, inferior to it in kind or Richness of Colour. I chose to employ the Spirit of Salt, rather than that of Nitre or Aqua Fortis, in this Experiment; because I found the first named Liquor to dissolve Iron very well, if not better, though less furiously, than Aqua Fortis itself; and also, because I could by this means better judge of the Tincture of its Colour; having formerly found by Trial, that Spirit of Salt makes a Green Solution of Mars; but Aqua Fortis or Spirit of Nitre, a Reddish one. And it was to judge of the Tincture of the Loadstone, as well as for another purpose, that I was so careful to keep the Stone from touching Iron, when it was pulverising; lest by the Hardness of it, and the Sharpness of its Angles, it should grate off some parts of the Metal, and so alter the Solution; for want of which Caution, I have known some Experiments about Artificial Gems to miscarry; the Brass Morter wherein the hard Ingredients were beaten, having communicated some Particles to them, that altered the Colour which the Mass after Vitrification would otherwise have been of.   

EXPERIMENT XIV.  
Some Parts of the foregoing Experiment may be confirmed by that which follows.  
I caused a weak Loadstone to be heated red hot, to make it the more easy to be powdered, and having caused it to be beaten very fine, I digested good Spirit of Salt upon it. (I afterwards found that ordinary Spirit would serve the turn) This in a few Hours acquired a Tincture not greenish, but almost like that of a troubled Solution of Gold. It strongly relished of Iron, and a little of it being dropped into Infusion of Galls, it turned it immediately into an Inky Liquor; part of this Solution being gently Evaporate ●, grew thick like an Extract, but did not seem disposed to shoot into Crystals; yet another part of it did precipitate with Salt of Tartar, much like a Solution of Vitriol; and another with Spirit of fermented Urine gave a plentiful, but yellowish red, Praecipitate.   

EXPERIMENT XV.  
Meeting among my loose Notes, with one that may serve both for a Variation and Confirmation of what has been above delivered in the Experiments; it seemed not improper to annex a Transcript of it.  
A red Mineral, whose Consistence was between Stony and Earthy, was by me judged to be a kind of Iron Oar, though having powdered some of it, I could not find that a good Loadstone would attract any part of it: Therefore, to satisfy myself, and to confirm D. B's Observation; about the Virtue of Linseed Oil, I caused this red Powder, wetted with that Liquor, to be kept about two Hours Ignited in a Crucible; by which means it was turned blackish. This dark coloured Powder was taken out, and suffered to cool, and then would readily adhere to the same Loadstone, almost as if they had been a heap of filings of Iron. But the Operation of the Fire perhaps contributed, as much (or more) as the Linseed Oil, to this Change. For a parcel of the red Powder being kept Ignited in a Crucible, though without the Liquor, did afterwards appear Magnetical.  
After having said thus much of the most useful of uncommon Stones, the Magnet: It will not, I presume, be thought incongruous to subjoin some Remarks about the most precious of them that are known among us, viz. Diamonds; which will be done in the next Chapter.    

CHAP. II.  
CONTAINING Various Observations about DIAMONDS.  
DIamonds being generally esteemed the most Noble and Precious of Gems, and even of Inanimate Bodies here below, (for of Carbuncles, the very Existence is disputed;) the Opportunity I had of being one of the Committee or Directors of the English East-India Company, (whereto the desire of Knowledge, not Profit, drew me) allowed me in some measure to gratify my Curiosity about them, by adding to some Observations of my own, the Answers I had to the questions, I propounded to some East-India Merchants and Jewellers, that had Opportunity to deal much with those Gems. Part of what I had learned about them, I committed from time to time to some Papers, which were the main things that supplied me with the following Particulars.  
These Gems, (to add that upon the by,) may the rather deserve our Curiosity, because the Commerce they help to maintain between the Western and Eastern parts of the World, is very considerable. For as small as their Bulk is, their Properties and men's Opinion, do so much recommend them, that I remember one of the most famous and intelligent Merchants of this Nation, (who has been Governor of more than one Trading Company in it,) being enquired of by me about the value of the Diamond Trade; he answered me, That according to his well-grounded Estimate, there came from the East-Indies into Europe, one year with another, to the value of about 350000 Sterl. of which about 100000 l. came into England; which at present, because of the prudent Indulgence of the Government, and of the East-India Company, is become the Mart of Diamonds.  
I. To prove the great hardness of Diamonds, even in comparison of other Bodies, that are thought wonderfully hard, a famous Artist for cutting of Diamonds, in return to some questions I put him, affirmed to me, that he could not either Cut or Polish Diamonds with any thing but with Diamonds. And he further answered me, that if he should employ so rough a way, and such forcible Engines to cut Rubies or any other Stones, as he does to cut Diamonds, it would presently break them in pieces; which the Inspection of his Engine made very probable to me.  
II. A very skilful Cutter and Polisher of Diamonds (Mr. L.) being demanded by me, whether he found that all sorts of Diamonds were of equal Hardness, told me, that having dealt in Diamonds near twenty years in Amsterdam, and divers years in England, he perceived that there are of later years, brought over worse and worse sorts of Diamonds; so that he judges those of the old Rock (as he calls them) either to be quite spent in the Indies themselves, or at least to be seldom or never brought over to us. And he finds several of recent Diamonds, so soft and brittle in comparison of those of the old Rock, that he is oftentimes afraid, or unwilling to meddle with them, lest he should spoil them in the Cutting or Polishing.  
III. Notwithstanding the (lately mentioned) wonderful Hardness of Diamonds, there is no Truth in the Tradition, as generally as 'tis received, that represents Diamonds as uncapable of being broken by any External force, unless they be softened by being steeped in the Blood of a Goat. For this odd Assertion, I find to be contradicted by frequent practice of Diamond Cutters: And particularly having enquired of one of them, to whom abundance of those Gems are brought to be fitted for the Jeweller and Goldsmith, he assured me, That he makes much of his Powder to Polish Diamonds with, only, by beating board Diamonds (as they call them) in a Steel or Iron Morter, and that he has that way made with ease, some hundreds of Carrats of Diamond Dust.  
IU. 'Tis an Opinion received among many that deal in Gems, that as Diamonds are the hardest of Bodies, so the same Compactness, and their great Solidity, gives them also a proportionable Gravity, and makes them extremely weighty, in reference to their Bulk: And I saw in the Hands of a Virtuoso, a Book (that I could not procure) not long since put out by a French Jeweller, who as he affirms, has dealt very much in Diamonds; wherein the Author asserts, the great Ponderosity of these Stones, in comparison of other Bodies. But this Opinion agrees very little with the following Experiment, that I find among others, that I tried about Gems, Registered to this purpose.  
A rough Diamond somewhat dark within, did in a pair of Scales that would turn either way with the 32th part of a Grain, weigh 8 Grains, and eight Sixteenths. This Stone being with care weighed in Water, according to the Rules of the hydrostatics; its weight appeared to be to that of an equal Bulk of that Liquor, as 2 11/23 to 1. So that, as far as can be judged by this Trial, even a Diamond weighs not full thrice as much as Water.  
V. A famous and experienced Cutter of Diamonds, being asked by me, whether he did not find some rough Diamonds heavier than others of the same bigness, told me, that he did, especially if some of them were Cloudy or foul: Insomuch that showing me a Diamond that seemed to be about the bigness of two ordinary Pease or less, he affirmed, That he sometimes found in Diamonds of that bigness, compared together about a Carrat (or four Grains) difference in point of weight.  
VI The shape or figure of Diamonds is not so easy to be securely determined. For those that are seen in Rings and other Jewels, having been by way of Preparation cut and polished, have changed their natural Figures for that which the Artificer thought fit to give them. And rough Diamonds themselves (which are not obviously met with) do oftentimes come to our Hands broken, though unwillingly, by the Diggers. And thereby unfit to acquaint us with their genuine Shape, which we may also miss of being able to discover, on account of the Accidents that the matter they consisted of was subject to, at their formation in the Mine. For to omit other Proofs, having had a Parcel of between 100 and 150 (if I misremember not the Number,) put into my Hands at one time in the East-India House to gratify my Curiosity, I found very few of them completely shaped; but most of them broken, and of very irregular Figures, like those of so much Gravel taken up at adventures upon the Seashore. But some few I saw that were pretty regularly figured, which probably were not much hindered from shooting freely in the Wombs or Cavities, wherein they were Coagulated or Concreted. And these seemed to consist, in my opinion, of several Triangular Surfaces that were terminated in, or composed, divers solid Angles. And one rough Diamond I had of my own, wherein this Shape was more conspicuous than I remember to have seen in any other. Besides having enquired of a very experienced Artificer, who dealt much in fitting these Gems for the Goldsmith's use, whether he found rough Diamonds to be of any constant Figure, and if he did, what that Figure was? He answered me, That he always found those that had any constant, (or as he meant, regular) Figure, to be in his own Expression six corner'd.  
VII. Diamonds have in them a Grain (or a determinate tendency of their Fibres, or rather of the thin Plates they are made up. of,) as well as Wood, and may with case enough be split along the Grain, though not against it; as I have seen a very large Diamond that was cut according to the Grain into three pieces, whereof the middlemost, though large and about the thickness of a Shilling, was of an even thickness, and exactly flat on both sides. I have myself a Diamond-Ring, whose Stone I would not have polished, but caused it to be set rough as Nature produced it, because in that state the Grain is manifest to the naked Eye, and much more to a Glass moderately magnifying the several Plates it consists of, having their Edges distinguishable like those of a Book a little opened. A Cutter of these Gems that has had store of them to practise his skill on, answered me, That one good blow may split even great Diamonds, if it be given, as they speak, with the Grain; but against the Grain, he affirmed to me, as dexterous and expert an Artificer as he is, that he is not able so much as to Cut or Polish them.  
VIII. The common Colour of Diamond being generally enough known by sight, 'tis not needful, as it would not be to describe it by Words; but the most usual Colour of these Gems is not the only, of which they may sometimes be found. A great Traveller into the Eastern parts of the World assured me, That he had seen some of them that were of a pale bluish Colour: That famous French Jeweller as well as Traveller, Monsieur Tavernier, gives an account of a fair Diamond that he had of a very red colour; and that great. Ornament of our English Court the D. of R. told me, that she was Mistress of a fair one, which though not of a Ruby, was of a red Colour, but not having it at Hand, she could not then show it me: A Relation of mine, in the same Court, used to wear a Diamond Ring; which though the Stone was not great, he valued at a hundred Pound, because its Colour was of so fine a Golden yellow, that I I should have taken it for an excellent Topaz, but that he had satisfied me 'twas a Diamond to which agreed its great hardness, which gave an uncommon Luster. And I remember, that Surveying attentively a parcel of rough Diamonds newly brought from the East-Indies, I perceived among them, besides several lighter variations of Colour. One Stone that was all Green, and that to such a degree, that I doubted not that if it were polished land set, it might pass for an excellent Emerald; and I should have suspected this Gem to have been really of that kind, but that I found it among Diamonds that belonged to Merchants too Skilful in those Gems to be imposed upon; and which was more, the Stone being yet rough and uncut, I found it plainly to have the proper shape of a Diamond.  
IX. At the late return of the Ships from India, being present at the delivery of the Diamonds to the Owners, I observed one belonging to a Dutch Merchant whose Father was a Cutter of Diamonds, and bred him to the same Trade. The Diamond came from the King of Cholconda, it was shaped (like mine) with fix Triangular sides, which yet were neither regularly figured nor truly flat, some of them being a little Convex, and one of them having a manifest and odly-figured Cavity in it. But the Diamond being fair and flawless, and so thick, that the Merchant told me it would be too deep for one Ring, and that therefore he meant to split it into two. I had it weighed, and found it to amount to ten Charats (or 40 Grains). I could easily perceive the Grain of this Diamond, which the Merchant also acknowledged; who answered me, that he had never seen in Diamonds any Heterogeneous mixture enclosed. He further informed me, that there was brought him a large Diamond from Borneo, that was much darker than one I showed him; insomuch that he compared it to Soot; but when he had cut and polished it, he and others were much surprised to find it a fair and clear Stone, of very great value.  
X. The conjecture I have elsewhere proposed, that divers of the real Virtues of Gems may be probably derived from the metalline, or mineral tinctures, or other Corpuseles that were embodied with the matter of the Gem, whilst it was yet fluid, or soft, and afterwards concoagulated therewith: This conjecture, I say, may be much countenanced by the following Relation, which deserves a place in this Chapter, by reason of its pertinency to the Subject of it.  
I have long suspected that the matter whereof Diamonds mainly consist was, whilst it was yet in Solutis Principiis, impregnated with metalline, and more particularly with martial ones: But by reason of the dearness of those Gems, and some other impediments, though I have been Master of several Diamonds of differing sizes, cut, and uncut, yet I could never make a Trial capable of satisfying my curiosity, till having lately met with among other little curiosities that lay long neglected by me, some number of small Diamonds, that I had bought for Experiments; I considered that their being yet rough, and so in their Natural State might make them more fit for my purpose, and so it might that they were not so clear as those that we value in Rings, which probably argued their having more of Martial Tincture in them than I should expect in the more Diaphanous: Upon this account, I say, I took a moderately vigorous Loadstone (for 'twas none of the strongest I have had) and applied it successively to five or six of these small Stones, without perceiving it had any Operation on them: But when I came to apply it to one more, which looked somewhat duller than almost any of the rest, I found that it had in it Particles enough of an Iron nature to make it a Magnetical Body; and observed without surprise, that not only it would suffer itself to be taken up by the strongest Pole of the Loadstone, but when that Pole was offered within a convenient distance, it would readily leap through the Air to fasten itself to it.  
I have elsewhere mentioned some other Qualities of Diamonds, as besides their Electrical Virtue, this, That 'tis possible that some of them may without Fire or Intense Heat be brought to shine; though among all that I have Tried, I found but two that I could so make Luminous. One of these belongs to the King, and is Described at the latter end of our History of Colours; and the other is a very small one of my own; which either was quickly lost among other Stones of the same size, or quickly lost its Faculty of Shining. But, to avoid Repetitions, I shall here only add, that some few other Observations of a more peculiar sort than those delivered in the two foregoing Pentades, may be found in other Writings of ours, to which they seem more properly to belong.   

CHAP. III.  
Many Changes of Colour produced by one simple Ingredient.  
I Know not any way more likely to Convince the generality of Men (who are wont to be much more impressed on by sensible Phenomena than Theories, though solidly Founded) how great an Interest the variable Texture of Bodies may have in making them appear of differing Colours, than by showing how the addition of a single Ingredient that either is Colourless, or at least is not of any of the Colours to be produced, is capable (and that for the most part in a trice) by introducing a secret change of the Texture to make the Body, 'tis put to, appear sometimes of one Colour, sometimes of another, according as the parts of the Body wrought upon are disposed to receive such a change as Modify's the incident Beams of Light after the manner requisite to make them exhibit a Blue, a Green, a Red, or some other particular Colour.  
Upon this Consideration I thought of several Liquors, such as Aqua fortis, Oil (as they call it) of Vitriol, or instead of it of Sulphur. Aqua Rezia, besides other Saline Liquors that I shall not now stay to name, because it may here suffice to tell you, that amongst them all I made choice of the Spirit (not that which Chemists call the Oil) of Salt, as that which is very simple, and which if it be not too much dephlegmed, may be had clear and Colourless enough. With this Spirit, I proceeded to make the following Experiments upon several Bodies, whose differing Textures made me suppose they would be fit for my purpose. And though I could not, without much disadvantaging my Design, forbear to mention some Trials that may be found elsewhere scattered among my Writings on other occasions; yet the greatest part by odds of those laid together in this Chapter, will, I presume, be found New.  
I. Some drops of well Coloured Syrup of Violets being let fall together upon a piece of white Paper, if a third or fourth part so much Spirit of Salt be with the tip of one's Finger mixed with them, the Syrup will presently become of a Red Colour, usually somewhat inclining to Purple.  
II. But if the Liquor to be Acted on, be otherwise disposed, 'tis possible with Spirit of Salt to turn it from a Blue Colour, not to a Red, but to a Green, as I have sometimes done by letting fall into a deep Solution of Filings of Copper made with an Urinous Spirit, as that of Sal armoniac, just as many drops of Spirit of Salt as were requisite and sufficient to produce the change intended. I say just so many Drops, because a very small error either in excess or defect, may leave the mixture still Blue, or bring it to be all Colourless.  
III. Upon a quantity, not exceeding many Drops of good Syrup of Violets, let fall two or three drops of good Spirit of Urine, Hartshorn, or the like, or of Oil of Tartar per deliquium; and when by mixing them well, the Syrup has acquired a fine Green Colour, then by putting to it a little of the Spirit of Salt, and stirring it with the tip of your Finger, you may turn the Green Syrup (as in the first Experiment you did the Blue) into a Red.  
IV. If you put a quantity of Red Rose Leaves well dried into a Glass Vial almost full of fair Water, and soon after put to them as much Spirit of Salt as will make the Water pretty Sharp, you will quickly see both that Liquor and the contained Leaves brought to a fine and lovely Red, which Scarlet Colour it will retain for a great while; the like effect Spirit of Salt will have on some other Vegetables of a Styptic or of an Astringent Nature.  
V. But if by infusing Brazil in fair Water, you make a Tincture of it, which you may much deepen by drooping into it a little Spirit of Hartshorn, or of Urine; if you then put to it a little Spirit of Salt, it will presently change it from a deeply reddish Colour, oftentimes like that of Muskadine, to a Colour far more pale, or rather yellow, like that of the more dilute Sack; so that the same Spirit acting upon two Vegetable Tinctures differingly disposed, draws out and heightens redness in one, and destroys it in the other.  
VI If you make an Infusion of true Lignum Nephriticum in Spring Water, it will appear of a deep Colour, like that of Oranges, when you place the Vial between the Window and your Eye, and of a fine deep Blue when you look on it with your Eye placed between it and the Window. But if you shake into this Liquor a few drops of Spirit of Salt, the Caeruleous Colour will presently vanish and appear no more, in what light soever you look upon the Vial, though the Liquor will still retain the Orange Colour.  
VII. We took common Writing Ink, and having let fall several Drops of it upon a piece of white Paper, so that when it grew dry in the Air, some parts of the Ink lay thick and some thinner upon the Paper whereon it did spread itself, we put a few Drops of strong Spirit of Salt, some on one part of the blacked Paper, and some (or perhaps a small Drop) on another, and observed, as we expected, that in these places, where the Spirit had been put, or to which it reached, the blackness was quite destroyed, and succeeded by an unpleasant kind of Colour that seemed for the most part to participate of Yellow and Blue, neither of them good in its kind.  
VIII. If in Spirit of Salt, you dissolve Filings of Steel, and slowly evaporate the filtrated Solution, it will shoot into a kind of Vitriolum Martis that will be Green as well as that which Chemists vulgarly make with Oil of Vitriol. And to add, That on this occasion, if you take these Crystals made with Spirit of Salt, and when they are dry, keep them in a Crucible, you will find that even a moderate Fire if duly applied, will make them in a short time exchange their Green Colour for a Red, like that of the finer sort of Crocus Martis, as indeed this Operation makes them referable to that sort of Medicines.  
IX. We took some Mercury precipitated, per se (that is, by the sole Action of the Fire, without any saline additaments) and though crude Mercury is not as far as I have tried, soluble in our English Spirit of Salt; yet this Red Precipitate (which is supposed to be mere Mercury) with its own Sulphur extraverted, did readily enough dissolve in that Liquor, and if I very much misremember not, did not at all impart its own Colour to it: And I also found that Red-Lead or Minium being boiled a while in good Spirit of Salt, the Redness did totally disappear. So that the same Agent that produces Redness in divers Bodies, did in those two, I have been mentioning, more than change it, since it quite abolished it. Of which also, I can give you an easier instance, by observing that the Reddest Coral being dissolved in our Menstruum, the Redness vanishes, and the Solutition appears Colourless.  
X. Take Filings of Copper, (the smallest are the fittest for this Experiment), and having poured on them good Spirit of Salt till it swim, about two finger's breadth over them; keep the Vial in a pretty strong Heat (in a Sand Furnace) till you perceive the Menstruum has dissolved a competent part of the Metal: Then warily take out the Vial, and holding it between your Eye and the Light, you will perceive the Solution of Copper to be not like that of Steel formerly mentioned, of a Green Colour, but of a dark and troubled one, oftentimes inclining to a deep, but muddy Red.  
XI. But if you pour this Solution into a wide-mouth Glass, and let it stand for a competent time, (which sometimes amounts but to a few hours, and sometimes to very many) the exposed Liquor will appear of a Green, much finer than that of the Crystals of Mars.  
XII. Take filtrated and limpid Solution of Silver, or of Mercury made in Aqua fortis, and drop upon it some Spirit of Salt, by which you shall find the clear Liquor turned white as Milk, which after a while will let fall a precipitate of the same Colour.  
XIII. And if instead of a Solution of Silver or Quicksilver, you take a Red Solution or Tincture of Benjamin, or of the Resinous part of jalap Root, or you'll also have upon the Affusion of Spirit of Salt, a white Liquor and a Precipitate of the same Colour.  
XIV. Being desirous to produce two differingColours at once by the same Affusion of Spirit of Salt, I infused some dried red Rose leaves in fair Water, till it had acquired a deep Colour from them. To this Infusion, poured off warily, that it might be clear, I added a considerable proportion of the sweet Liquor, made by digesting Spirit of Vinegar upon red Lead, by which I knew 'twould be turned of a Bluish Green. Upon this almost opacous Liquor, I poured Spirit of Salt, which as I expected, precipitated the Lead that had been dissolved in the sweet Liquor, into a very white Powder, and gave the remaining Liquor, well impregnated with particles of the Rose Leaves, a very fine and durable Scarlet Colour. To which Experiment I shall add on this occasion, that if it had been well made, you may barely by shaking very well together and confounding the White Powder with the Red Liquor, make a Carnation Colour, which (when 'tis made as it should be) appeared very fine and lovely whilst it lasted, for in no long time the two Substances that composed it, would by degrees separate, and reappear each of them in its former place and Colour.  
XV. We took some Spirit of Salt, that having lain long upon Fyling of Copper, had lost the muddy Tincture it had first acquired by being almost boiled upon them. This Liquor, I say, that looked like common Water, we poured into a small, but wide-mouthed Christal-Glass, about half an hour after 8 in the Morning, and leaving it in a Window, it appeared after 40 Minutes to have there acquired a Colour, much like that of a Germane Amethyst, and seemed to have no tendency to Greenness. But being detained by the visit of a Virtuoso till eleven a Clock, I could not see what happened in the mean time: But then as he was going away, I invited him to see the Liquor, which he (not knowing what it was) told me it looked of a Grass-green Colour, wherein though I were not altogether of his mind, yet in a short time after, it did to me also appear of a lovely Green; in its passage to which it had in all been exposed about 3 hours and a half  
XVI. Precipitate a strong Solution of Sublimate, (made in fair Water) with a s. q. (and no more) of Oil of Tartar per deliquium. Put the Liquor and Powder into a Filter of Cap-paper, and when the Water is run thorough, there will remain in the Filter the Precipitate, which is to be slowly and well dried. Then take it out of the Filter, in the form of a gross Powder, and having put it into a clear Glass, let fall on it warily some Drops of pretty strong Spirit of Salt, and (if the Experiment succeeds with you as it did with me) during the Conflict that will be made, the little Lumps of the Precipitate will lose all their former Brick-dust Colour, and turn White, though afterwards they will appear dissolved into a transparent Liquor, wherein the Orange Colour is quite abolished.  
XVII. Having calcined Copper without any Additament, save Fire and Water (by the way we elsewhere mention) we took an Arbitrary quantity of it, and having poured on it about 3 or 4 times the quantity of good Spirit of Salt, we obtained (what we looked for) both a Muddy, but manifestly Reddish Liquor, and (somewhat to the surprise of the Persons I had a mind to satisfy) a white Powder, whose quantity bore a considerable proportion to the Part that was dissolved, (but whose Qualities belong not to this place) In which part its self, (to add that upon the by) by the affusion of common Water, and the action of the Air, we afterwards produced more than one change of Colour.  
XVIII. We sometimes for Curiosity sake took a quantity, not exceeding a spoonful, of the dark brown or somewhat reddish Solution of ♀, mentioned in the foregoing Experiment, and having put it into a cylindrical Vial, that the change of Colour may appear the better, we poured on it 2 or 3 Spoonfuls of totally ardent vinous Spirit, and giving the Glass a shake to mingle them, we presently had (as soon as the mixture became clear) a lovely green Liquor, which when 'twas well settled, was very fair, and looked almost as if it were a liquid Emerald.  
XIX. We took some green Taffatee Ribbon, and having moistened one part of it, that was not great, twice or thrice with good Spirit of Salt, we suffered it to dry of its self; which it did in a short time, and then we found as we expected, that the wetted part was no longer of a Green, but changed to a Blue Colour. But the same Spirit, (to add that upon the by) presently turned that part of a piece of black Ribbon, upon which we put 2 or 3 Drops of it to a Colour not unlike that which they call Fueille Morte, or, a fading Leaf.  
XX. 'Tis usual in Paper-shops, and in divers other places, to meet with Pamphlets and other thin Books that are covered with Papers that look sometimes of a Greenish Blue Colour, bordering upon Purple, and sometimes upon that of Violets. Some of the deeper coloured Papers of this sort, I have several times to gratify some curious Persons, especially of the Sex, held in my left hand, and with the other lightly and nimbly touched them here and there with the end of a feather (cut off from the rest of the Quill) dipped in Spirit of Salt, which almost in the twinkling of an Eye, died the touched parts of the Paper with a Lovely Red, that would sometimes continue very Vivid for a good while, and be manifest at the end of divers Weeks, if not Months. And if instead of the forementioned Quill, I took into my right hand (a Brush, or) somewhat that was fit to sprinkle with, and having dipped it in the Saline Spirit, made many drops at once fall upon the Paper, 'twas pleasant enough to behold how suddenly and prettily it would be Speckled.  
XXI. We took Antimony well powdered, and poured on it 3 or 4 times its weight of good Spirit of Salt; we caused it to be boiled in this Liquor, (and that in a Glass Vessel) wherein a part of it was dissolved, and taken up into the Menstruum; where the Antimony quite lost its blackness. And this thus impregnated Spirit of Salt, being dropped into fair Water, the black Mineral subsided immediately, in the form of a very white Powder or Precipitate.  
To these I might add other changes of Colours, that I have made, by the help of Spirit of Salt. But these being not of so quick and easy Trial, (especially because some of them require skill in Chemistry) I thought it not fit to annex them; supposing that those already delivered, amounting to above four Pentades, may suffice for the purpose declared at the beginning of this Paper. And also to afford us this Reflection, That it may not be amiss, if Physicians, Chemists, and others that are wont to compound Drugs, or other Ingredients; would be less forward than they usually are, to mingle, not to say to jumble, several of them together, either unnecessary, or without due regard to the friendly and incongruous Qualities (in reference to one another) that the separate Ingredients may have. For most of us are but too liable to be mistaken, when we presume beforehand, what changes the Coalition, or other Associations of differing Bodies may produce; especially if they be either Saline, or plentifully partakers of a Saline Nature; Since Experience frequently shows, that by the Action and Reaction that are consequent upon untried ways of Composition, there Emerge in the mixture new Consistences and other Qualities or Accidents, that were not looked for, when the Ingredients 'tis compounded of, were put together. And though it may sometimes happen luckily enough, that these Emergent Qualities, whether of Drugs, or other Comparatively simple Bodies, may prove advantageous; yet this may well be looked upon but as a lucky chance; and hinders not, but that one may justly fear that ordinarily the newly produced quality of a Medicine, may prove to be either worse than was expected, or at least other than was designed, and consequently less fit for the Physicians or the Artists determinate purpose.   

CHAP. IU.  
An Advertisement touching those Passages that in this Book relate to the Art of Medicine.  
THE favourable Reception the Public was pleased to give two Editions set forth in one Year of The Usefulness of Experimental Philosophy, having Encouraged the Stationer to Solicit me for a new Impression, I was on the same ground invited to think of making additions to divers parts of that Treatise; but afterwards observing that notwithstanding the Thanks and Acknowledgements I had the good fortune to receive from several Physicians (some of them of great Reputation, and perhaps by that only known to me) yet others were not well pleased that a Person not of their Profession should offer to meddle with it, though with a design of advancing it: I, whose condition exempted me from taking upon me their Calling, and who consequently must want many opportunities that others enjoyed of making Observations about the Phaenomena of Diseases and of Medicines, suffered myself without much violence to be diverted to other Studies more suitable to my Inclinations, as well as to my Condition, and accordingly I laid aside the Papers I had Written in reference to the Physicians Art, nor were it easy, or perhaps possible for me to retrieve them, after they have lain so many Years dispersed and neglected, by which means perchance divers of them have been lost.  
But all this could not hinder me from being pressed to retrieve and communicate these scattered and dusty Papers by the Secretary of the Royal Society Mr. H. Oldenburgh: For as this Gentleman has been almost every where wonderfully solicitous to preserve every thing from being lost, that may any way contribute to increase the stock of useful knowledge. So having got notice of these Papers, and a sight of some of them, his partiality for me made him much over-value them, and persuaded him that a Collection of them as incoherent and unfinished as they were, might be of some use to the Physicians Art. And this seemed the more hopeful, because Natural Philosophy being a Science of far greater Extent than Physic, and supplying it, with many of its Principles and Theories; 'tis very Possible that Naturalists, though not Professed Physicians, may propose some such comprehensive Notions and Methods, as may awaken and enlarge the minds of them that are so, and at least afford some useful hints to considering and ingenious Men. And in effect divers Physicians, as well as many Patients, have been pleased to declare (some in Print, and some other ways) that sometimes they found not useless assistances from some of those Papers, wherein I occasionally touched on Medicinal things. Such Motives as these made Mr. Oldenburg so earnest to procure the scattered Fragments, that I might have yet remaining, about Medicinal Affairs, that though for the Reasons mentioned above, I could not think it fit to make a Collection of Papers so unlike in their Subjects, so disproportionate in their Bulk, and so unfinished and imperfect on divers scores; Yet thus far I was content to comply with his desires, that when these Trifles came to hand, I would now and then insert them among my Experimenta & Observationes Physicoe. (Medicine being a Part, or an Application of Natural Philosophy) especially if there were any great affinity between the Paper I lighted on, and the Subject I was then treating of: Knowing well that Mr. Oldenburg, and perhaps some others too, had rather I should impart them at all adventures, than suppress what they judged might be useful; and that 'twas better to run the hazard of having them slighted, than lost.  
This Advertisement I thought fit to give in this place, once for all, that when hereafter there shall occur any thing among these Experimenta & Observationes Physicae, that directly relates to the Physician's Art, you may not think it strange, remembering upon what account I ventured to meddle with things of that Nature, and also that you may readily understand what I mean, when you meet with any Particulars delivered, as Thoughts or Desiderata or Wishes, tending to, or aiming at the Improvement of Medicine; which how slight or superfluous soever they may be to Experienced Masters, to whom I did not presume to recommend them, I thought might probably be serviceable to a very Ingenious, but yet Young Cultivator of that noble Art, (whose Name, I concealed after the way of the Curious of Germany under that of Trallianus,) for whose use they were intended.  

The I. PENTADE.  

EXPERIMENT I.  
A very Tall and well Set Gentleman, Aged about 24 years, by a Fall from his Horse, had his Skull broken in several places, and being a Person of good Estate, had several Surgeons to attend him in the course of his Sickness; during which he was divers times Trepan'd, and had several pieces of his Skull taken off, which left great Chasms (that I have seen and felt) between the remaining Parts. Within about three days after his Fall, this Knight (for so he now is) was taken with a Dead Palsy on his Right Side, which did not equally affect his Arm and his Leg: The use of the latter being sometimes suddenly Restored to him in some measure, and (though seldom) after a while almost as suddenly Lost: But his Arm and Head were constantly Paralytical, being wholly deprived of Motion; and having so little Sense, that it would sometimes lie under his Body without his Feeling it. But if his Hand were pricked with a Pin, he could take notice of it. This Palsy continued during almost the whole time of the Cure, which lasted 23 or 24 Weeks. And when the Surgeons were going to close up his Head, as having no more to do; one of them who was an Ingenious Man, and Tenant to this Gentleman, opposed all the rest, alleging, that, if they did no more, the Gentleman would lead an Useless and very Melancholy Life; and that he was confident, the Palsy was some way or other occasioned by the Fall, which had left something in the Head that they had not yet discovered. And the Knight himself agreeing to this Man's motion, his Head was further laid open; and at length, under a piece of proud Flesh, they found, with much ado, a Splinter, or rather Flake, of a Bone, that bore hard upon the dura mater, and was not pulled out without a great Hemorrhage, and such a stretch of the Parts, as made the Patient think his Brain itself was tearing out. But this Mischief was soon Remedied, and his Hurts securely Healed up; and he is now a Strong Healthy Man, and finds no Inconvenience by having so broad and various a Callus instead of the Skull; save that he is a little obnoxious to take Cold in his Head. But the memorable Circumstances, for whose sake I mention this Narrative, were these: When I asked him how big the Bone was, that was last taken out? He told me, that it was less than half the Nail of one of his Fingers (not his Thumb) and that it was almost as thin, being in size and shape like the Scale of a Fish: But that it did not in his Head lie flat, but bore hard upon the dura mater. When I asked him how long after it was taken out, he began to feel some Relief, as to his Paralytic Distemper? He replied, That in less than five hours he found himself, to his great joy, able to move his little Finger; and (though this happened in the Evening) he was the next morning able to move all his Fingers, and within 2 or 3 days after to lift up his Arm: By which it seemed manifest, that so little a Body as the Splinter lately mentioned, produced in so robust a Person, a Palsy of the whole side it lay on. For when I particularly asked him, Whether, after the taking away of the proud Flesh that encompassed the little Bone, he did not find, if he found none before, some Relief as to his Palsy? He answered, that he found none at all, till the Bone had been pulled out, which was not till a good while after the Chirurgeon had been by degrees eating off the proud Flesh that, grew about it. But there was in this case another Phoenomenon that I thought little less considerable than the former. For, remembering the important controversy, that is agitated among modern Physicians and Anatomists, about Nutrition by the Nerves, and having thereupon asked this Knight, whether he did not find an Atrophy in the Limbs of his Body that were affected? He told me, that when he began to be Paralytic on that side, it by degrees much wasted, and the Paralytic Leg was very much Extenuated: But the Arm and Hand much more, seeming nothing but a System of Bones, with the Skin pasted on them. And when I further asked, if upon the removal of the Bony Splinter abovementioned, the Atrophy of the Parts did not also begin to lessen; he answered affirmatively, and told me, that in no very long time his Leg and Arm recovered their wont Dimensions; and in effect I (some days since) saw the restored Arm well plumped up with musculous Flesh, though the Wether were exceeding Cold. And he further told me, that he found no difference between the Limbs that had been Paralytic, and the others, except that they would grow sooner and more sensibly cold in Sharp or Frosty Wether.  
This Gentleman answered me, to add that upon the by, that, during the course of his Cure, he was very frequently (almost every second day) let Blood; that he wanted not Appetite to his Meat; that for the most part he slept indifferent well; and, which was more remarkable, upon so great a Hurt of the Head he did not Vomit, not had afterwards any Convulsions.  
II. Among other Instances I have met with, that show the great Power which sudden Passions of the mind may have upon the Body, I remember that a Woman of middle Age, complained sadly to me of the mischief, a Fright had done her; for she related to me, that having taken along with her to a Meadow by a Riverside, a little Boy that she was dotingly fond of, whilst she was busy about the work she came thither for, the Child stole away from her, and went along the Bank, to delight himself with the View of the Stream; but being heedless, it seems by Circumstances, that he set his Foot upon some piece of Ground that the Water had made hollow; upon which account, the Earth failing under the weight of the Boy's body pressing it, that, and he fell together into the River: In the mean time the poor Mother casually missing her Child, hastily cast her Eyes towards the brink of the River, and not being able to see him there, she presently concluded him to be Drowned, and was struck with so much horror upon the sudden accident that tore from her a favourite Son, that among other mischiefs, she fell into a Dead Palsy of her right Arm and Hand, which continued with her in spite of what she had done to remove it, till the time she complained of it to me, who had not opportunity to know what became of her afterwards.  
III. On the other side, to show that Violent Passions, and even Frights may sometimes, though very seldom, do good, as well as harm; I shall here add a Relation that was circumstantially made me by the learned Person himself, to whom the Accident happened. I familiarly knew a Gentleman that lived to be an Eminent Virtuoso, and to oblige many by his useful Writings, who when he was a Youth, fell into a violent and obstinate Sciatica, which continued with him so long, that it left him little hope of Recovery; but the Devotion of this Young man's Friends invited them to make him be carried, since he could not go, to Church upon Sundays; and there it happened, that the Town being a Frontier Garrison, the Guards were so negligent, that there was occasion given to a very hot Alarm, that the Enemy was got into the Town, and was advancing towards the Church to Massacre all that were in it. This so amazed and terrified the People, that in very great and disorderly haste, they all ran out of the Church, and left my Relator in his Pew upon a Seat that they placed him, and whence he could not remove without help: But he being no less frighted than the rest, as they forgot him, he forgot his Disease, and made a shift to hamper off the Pew, and follow those that fled; but it quickly appearing, that the Alarm had been a false one, his Friends began to think in what a condition they had left him, and hastened back to help him out of the Pew, which whilst they were going to do, they, to their great surprise found him in the way upon his feet, and walking as freely as other Men. And when he told me this Story, he was above forty years Elder than when he was thus strangely rescued, and in all that time, never had one Fit of the Sciatica.   

ADVERTISEMENT.  
'Tis easy to be observed, that of the two kinds into which Chemists may be conveniently enough sorted; the Number is greater of those that are not Professed Physicians, than of those that are: And yet several of the former sort are led by their more free Curiosity, or their particular Designs, to allow a large scope to their Trials; and so in their Experiments upon various Bodies, to operate upon some of those that may be reduced (either directly, or by sit applications) to the Materia Medica, and afford uncommon Preparations: Which though designed for other purposes, may by a skilful Physician, with a light Variation, and perhaps without any, be made to afford good Medicines: And therefore I think it may be no inconsiderable service to the Public, if by the leave and assistance of the Authors, divers Chemical Experiments that are not directly useful to their immediate purpose, were not, (as is usual) thrown away, but put into the hands of some Sagacious Physician.  
Upon these grounds, I thought myself little less than obliged, to set apart now and then an Experiment that contained some uncommon Preparation, which seemed applicable to Medicine; and to try whether, though, being in the Country or in some other inconvenient Circumstances, I had not opportunity to prove it myself, the notice given of it, might not happen to be of use to a skilful Physician.  
I shall therefore partly in this Chapter, and partly (if God permit) in some following Chapters and other Writings, tender to such a one, some few of the Experiments of this sort, that I lately lighted on among my Adversaria, and that seemed not uncapable to be made of some service to the Physician's Art.  
Of the good and bad effects of these, I shall be glad to be informed, that they may be either used more freely and improved, or corrected and quite laid aside; and I desire that this short Preamble may serve for a general one to all the other designed Chemical Medicines that I shall venture to propose hereafter.   

A Designed Chemical Medicine.  
IV. I know how much Men are prejudiced in some whole Countries, against Vomitive Medicines: and I remember we have had here in London a Physician of great Fame and Practice, that would turn over a Patient to another Doctor, if the Case were such that the Patient would needs make use of Emetics. And I readily acknowledge that they are edged Tools, that require a Skilful Hand, to employ them without danger of doing more harm than good: But since Experience shows that where the Patient can bear them, and the Disease requires them, they act more speedily and effectually than other evacuating Medicines: And since the generality of our Physicians, not excepting some that are justly reputed very Cautious, do not scruple frequently to make use of the Infusion of Crocus Metallorum, though it do not seldom prove a Remedy harsh enough; I shall venture in compliance with some ingenious Physicians, and others that have often made use of a Medicine, that goes under the name of my Emetic Drops, to communicate the Preparation of them; without pressing the use any otherwise than by confessing that divers Practitioners of Physic of differing Sentiments, agree in assuring me, that they have not yet found any Emetic to work so effectually, nor with more ease and safety, than this Liquor; which some of them prefer by much to other Antimonial Vomits; and especially to the Infusion of Crocus Metallorum.  
In preparing my Vomitive Liquor, I have not always employed the same proportion of the Ingredients 'tis made of, nor did I find it necessary to be nice in that matter. But the proportion I somewhat prefer, is to take two Parts of well chosen and finely powdered Antimony, and on these to pour three Parts of the Menstruum, viz. Sp.; which ought to be rather moderately strong, than too much rectified. These are to be distilled together in a Glass Retort fitted with a Receiver not very small, till there come over a great part of the Menstruum, which will usually towards the close be accompanied with Red Flores, (some times copious enough) which being separated by filtration through Cap-paper, the clear transmitted Liquor is to be put into a Glass, not newly washed, but dry on the inside, and to be kept close stopped from all Intercourse with the Air.  
The Dose is usually to a Man or Woman, especially at the first time, from 4 or 5, to 7 or 8 Drops: But I know an Ingenious Physician that gives to 10 or 12, or a few more Drops, if the Case be urgent; and by that means he told me, that with a small Button-Bottle, that I chanced to give him a little before, he did in 2 or 3 hours rescue three Gentlemen, that by a bad Surfeit with very bad Circumstances, were suddenly brought into great danger of speedy Death, and carried to a neighbouring Tavern, as being too ill to be carried home.  
The Vehicle may be a Spoonful or two of Wine, or Blackcherry Water, or (which divers Persons choose rather) of Spring-Water, Drinking up the Liquor immediately after, because there will some Precipitation be made; and then taking 2 or 3 Spoonfuls of the same Vehicle to wash it down. It usually begins to work early, and does it without causing near so much straining as vulgar Emetics, and yet makes Copious Evacuations; and sometimes so Eradicative of the Morbific matter, that the Physician lately mentioned, who Cured the three Gentlemen, having a poor Patient who had Conflicted for above three Years with an Ague in several Types, but most commonly Quartanary, perfectly Cured him with two Doses of these Drops, and a Julap made chiefly of the Distilled Water of a common Vitriolic Mineral. And this Cure seemed therefore to me, when the Physician gave me an account of the Drops he had from me, the more considerable, because the Patient had made use of great Variety of Remedies; and particularly he devoured great store of the Jesuits Bark, or Cortex Peruvianus, (perhaps because it was not well Conditioned, or skilfulfully Administered) which sometimes altered the Type of his Ague, turning it to a single or a double Tertian, and sometimes kept off the Fits for a while, when 'twas a Quartane, but never Cured him quite; and left him in a deplorable estate, wherein the Emetic Drops found him.  
Tho I sent this Medicine to several Patients, in whom, thanks be to God, it succeeded more than ordinarily well, yet I durst not venture to give it to Children, or to very young Persons; but having gratified an Ingenious Surgeon of good Practice, with a stock of it, the Trials he made upon divers Persons, with great Success on other Patients, emboldened him to give it to Boys and Girls, and afterwards even to several Children, whereof he gave me a good Account, only he discreetly took care to proportion his Doses to the Age and Strength of his Patients, and not to give the whole Dose at once, but divide it into 2 or 3 parts, that if the first should work within half an hour or less, the second should not be given, or lessened in quantity. And if neither the second did work within about an hour, he added the third. And by this Cautious Method, he assured me that he had suddenly relieved several Children in bad Cases, and found not any mischief or danger ensue upon the administration of it. But Children being tender Creatures, this is to be further and cautiously tried.   

POSTSCRIPT.  
Having had occasion to keep by me some Vials furnished with the Emetic Drops, longer than I thought I should need to do so: I observed that in tract of time, there, began to subside a white Powder, wherein a good part of the Emetic faculty of the Medicine may be supposed to reside; therefore 'twill be best either to employ the Liquor in no long time after 'tis made, or if one has not leisure or conveniency to do so, to shake the Vial well (that the Powder may be raised and we'll dispersed through it) just before it be administered.   

A Designed Chemical Medicine.  
There are many that having a high Esteem for Chalybeate Waters, such as those of the Spa and Tunbridg, which yet in many places are not to be had at all, and in few to be had well conditioned, are very Solicitous to find Succedaneums to them. To gratify some Ingenious Persons of this sort (and improve a casual hint taken from a Book of a somewhat like Preparation propounded for another purpose) I remember, I Employed a way of Emulating such Waters that answered the outward Phaenomena of Colour and Taste, and seem by the paucity and harmlesness of their Ingredients like to be innocent Medicines; I had no opportunity to make trial of them in Physic, but finding that some Inquisitive Cultivaters of that Art, valued them more than I did, I committed the Experiment to Paper, and now suffer it to come abroad, that it may be tried by Physicians, and either rejected or made use of, as success shall direct. The Experiment as I made it, was this.  
We took one part of very good Fyling of ♂; and ten parts of good Distilled Vinegar. These we put into a Bolt-head, and shoped it well, and then in a mild heat of Sand we digested them for about two days, and afterwards augmented the Heat till the Liquor appeared of a deep Orange Colour, but yet transparent. Part of this Tincture we poured off, and kept well stopped by its self, because though by a longer digestion and a greater heat, we obtained a very red Tincture, yet we did not so much value it, because when the Menstruum is over Impregnated, the Metal usually precipitates, and the fine Colour is destroyed. Of the first reserved Tincture, we let fall 4 Drops into ℥ VIIIss, (8 ℥ ss) of clear common Water, whose Colour was not thereby sensibly altered; and the Vial containing this Mixture being well shaken, that the Tincture might diffuse itself the more thoroughly, we kept it carefully stopped for use, as being our Factitious or Counterfeit Spa. A Spoonful or somewhat more of this, with about a quarter of a Grain, or less, of good fresh Powder of Gauls, would presently afford a Purplish Tincture, like that of Natural Springs impregnated with Mars, such as the Water of the Germane Spa, or of Tunbridg in Kent; if ones Mouth were Washed with it, 'twas found to have like those Natural Chalybeat Waters, a manifestly faeruginous taste. N. B. These Artificial Acidulae are to be Administered in no long time after they are made; for Experience has informed me, that (at least sometimes) when I kept them too long, within not many days after they were made, they would lose much, if not most of their Briskness and Force. And I sometimes perceive that there would subside to the bottom a certain red or reddish Substance, as it were Ochre, which was a token of the Degeneracy of the Liquor; and some such thing I have observed in some Natural Chalybeat Waters too long or negligently kept. But our Acidulae may be so soon and so cheaply made freshly, that the above mentioned Inconveniency will scarce to the Skilful seem considerable.    

The II. PENTADE.  

EXPERIMENT II.  
Because it may be on some occasions of use to a Physician, to have ways of Discovering the Adulterateness of Bezoar Stone, which for its dearness is often Counterfeited, and not easily discerned to be so by the common ways of Exploring, which use to be uncertain enough; it may not be amiss to Communicate a new way of Trial, which 'tis unlike that Impostors have dreamed of, or if they should know it, can easily elude. And this I am the rather willing to do, because the proposed way may afford an useful hint to the Sagacious Inquirers into the Nature, and some of the Preparations that may be made, of the Bezoar Stone; which though it be a Drug too much Magnified by some Physicians, especially those that depend on it, against the true Plague; yet a Physician of great Experience, and rather a severe, than any ways a partial Judge of it, allows it to be an excellent Remedy even in Malignant and ill-conditioned Fevers, at least if they be not truly Pestilential. One of the ways I employed, in treating the Bezoar Stone, may be easily gathered from the ensuing Transcript of one of my registered Experiments.  
We took 40 or 50 Grains of choice Oriental Bezoar Stone reduced to Powder, and in a Bolt-glass poured on it. ʒVI of good Spirit of Niter, as well to try whether this Liquor would prove a fit Menstruum for: this Stone, as we found it to be for the Calculus Humanus, as for other purposes. And though this Affusion being purposely made in the Cold, the Liquor did not seem at first to work on the Stone; yet soon after it fell violently upon it, and dissolved the greater part of it, not without noise and a Notable Effervescence. The Solution was almost Red, and the Glass being put in a digestive Furnace, the whole Powder was not only dissolved, but being left a night or two in a North Window, it afforded divers Saline Concretions, much larger than could well have been expected from so small a quantity of matter; and these Crystals, whilst they were yet in the Glass, might easily be taken for Crystals of Saltpetre, so great was their resemblance.  
To manifest how much the faculties of loosening and binding, are relative things, and depend upon the Disposition of the Body to be wrought upon, and so upon the Congruity betwixt the Agent, and the Patient, I know an Ingenious Gentlewoman, on whom Cinnamon, which generally is a considerable Astringent and Stomachick Medicine, has a quite contrary Operation, and that in a strange degree, insomuch that having found by 2 or 3 accidental Trials, that a very little Cinnamon seemed to disorder her Stomach and prove Laxative, she resolved once to satisfy herself, whether those Discomposures came by Chance, or no; and having strewed some powdered Cinnamon upon a Tost, she was going to put into her Ale, upon eating the Tost she was copiously Purged for two days together, and that with such violence, that it put her into Convulsion Fits, and a kind of Spasmus Cynicus, which she could never be perfectly freed from, being troubled with from time to time for. 3 Years, as was the other day averred to me, and divers others that know her, by her Husband who is himself a Learned Man and a professed Physician.  
A prosperous Physician, to whom I had recommended some things relating to his Profession whilst he practised it with Success in the Capital City of Ireland, where at that time there raged a new and violent Fever, whereof Multitudes Died, very few Patients Recovering of it, happily lighted on a Method that proved, through God's Blessing, very Prosperous. This Doctor returning into Ireland sometimes before, having been desired by me to send me an account of some things relating to Natural Philosophy and Physic that I named to him, wrought to me in answer to some of my Inquiries a Letter, out of which I thought fit to make this Extract, because I know not but that it may give good hints towards the Cure of some other ill-conditioned Fevers.   

Dublin, Feb. 27. 1682.  
I Have employed Ens Veneris for the removal of a Subsultus Tendinum, in a Person dangerously Sick of a Febris Petechialis (a Discase fatal to very many here for these 12 or 14 Months) and found that it answered my hopes in 3 or 4 Hours after I gave it in Conserve of borage Flowers.  
I have, since I came from England, thought of a Method of Curing the aforesaid Fever, which has not once failed me, though I made of it for 16 or 18 several Persons, many of which would certainly Die, if treated after the usual manner in this case. If I should tell you from what Observations and Reasonings I came to alter the Method of Cure, I should be very tedious. I shall therefore at present wave that, and proceed to tell you, That when first I come to any Sick of this Disease, if I find Costive (as generally they are) I prescribe a Glister, and after that an Episplastick Plaster 6 or 7 Inches broad, and 8 or 9 Inches Long, to be applied between the Shoulders; the Blister being well raised, I order to be Dressed carefully, stripping off the Cuticula. This continues running till the Fever is gone off; which is most commonly in 10 or 12 days, if they have not kept up too long with it, and then we cannot certainly foretell the time of the Fever's declination; for the whole time till the going off of the Fever, I Prescribe Emulsions of Aq. Aronis, Card. Bened. Citrij totius & Syr. Granatorum cum Aceto; I allow of Orange and Buttermilk Possets, of roasted Apples, Flummery, or any other light and cooling thing they call for.  
By this Method I keep the Genus Nervosum and Brain from being Affected, and consequently secure my Patients; for as many as I have ever known of them Dye, that were troubled with this Disease, Died of a disorder of those Parts. I do not defer the Blistering Plasters, as others do, till I find my Patients Delirious, Lethargic, Convulsive, or otherwise affected in their Heads and Nerves, finding by the Experience of others that than they most commonly prove ineffectual, because of some Morbific Matters being too deeply lodged in these parts. I do not prescribe, except upon some extraordinary occasions, any Volatile Salts or Spirits, or any thing too apt to quicken the already over-brisk Circulation of the Blood, having Experimentally Learned that by these often used, the Brain and Nerves become sooner than ordinary affected, for as much as they deeply insinuate themselves, and drive with them some Morbific Matter into the Brain and Nerves. I find Bleeding bad, being generally Fatal. If I doubt of the Recovery of any of my Patients Sick of this Disease, 'tis only when I find that they have been let Blood, or lain for 8 or 9 days before I come to them; though I have brought through it, even Persons in those Circumstances.   

A Designed Chemical Medicine.  
I shall not, because I need not, Discourse of the Medicinal Virtues of Steel in a City where many Learned Physicians do so much esteem and employ Chalybeate Medicines as they do in London, and therefore I shall content myself at this time to offer you a couple of Preparations of Steel that possibly you have not met with or thought of.  
1. Considering that most of the ways made use of by Chemists to prepare Steel, tend by dividing it into very Minute parts, to make it more liable to be wrought on by the Liquors of the Stomach, and some other parts of the Body, and that the generality of these Chalybeate Preparations are wont to be made only with Acids, whether manifest, as Oil of Vitriol, Spirit of Vinegar, etc. or Occult, as Brimstone, which though insipid in its Natural State, when it comes to be Melted, discloses its hidden Salt, and works on ♂ by a sharp Acidity; considering this, I say, and that Men have confined themselves to Acids in working on Steel, because they supposed Instruments of that kind were necessary to dissolve that Metal, I thought it might do you, and some Ingenious Men of your Profession, some little Service, if I proposed to you a way of Opening the Body of Steel, that though I gave a hint of it divers Years ago, is, for aught I know, yet unpractised.  
We took then several Ounces of highly rectified Spirit of fermented (or putrified) Urine made per se, and consequently without Quicklime, and poured it upon as much Filings of Steel freshly made, to be sure, not to have any Rusty ones, as we guest, would at least suffice to satiate it fully. These we put in a moderately warm place, where the Menstruum wrought on the Metal for divers hour together, and Dissolved a considerable part of it. This Solution we set to filter, and found it of a Taste considerably strong, but very different from any of the Chalybeat Preparations, we remembered, that were seen made with Acids. The Liquor being kept in a stopped Viol for some days near a Window, did in the Cold let fall by degrees a considerable quantity of Powder of a deep Green Colour, which surprised some Virtuosos, to whom I showed it, especially because the Liquor itself was not of that Colour; though at least the superficial part of what remained (in plenty) in the Filter, did also in the Air acquire a Green Colour. But though our Solution poured off from the subsided Powder, was warily and slowly evaporated, yet we did not find it would well Crystallize What use may be made in Physic, of Preparations of this kind, I leave to you, whose Profession as well as Curiosity will engage you to consider. I do not presume to tell you, but in general it seems that Steel Prepared with Volatile Spirits of the Animal Kingdom that are wont to be friendly to Nature, and are very contrary to Acids, may have new qualities very differing from those of Steel Prepared with Acids, and may be more safe in some Cases and to some Patients. With what other Volatile Menstruums I have dissolved Mars, and what Phaenomena some Trials I made with that Metal opened by such Salts, you may command an Account of, if you think it worth desiring.   

A Designed Chemical Medicine.  
Another Experiment that I made on Steel, was designed to make as much of it Volatile, as I could with a Menstruum, not so Corrosive or Dangerous to the Body as Oil of Vitriol, or Spirit of Niter, which, especially the former, are employed by divers Chemists to make Chalybeat Preparations that yet are not Volatile. The Medicinal Scope I had in my Eye, for I had also a Chemical one (that belongs not to this place) was to try if I could by it obtain any Sulphur of Mars, which the Commendations that some, even of those Chemists, whether Adepti or not, whose Authority I most regard, represent as an excellent Medicine, especially in Cases that require Anodynes, and which the others, or the same speak of as a graduatory Substance (as to some Metals) or both: If you should ask me, why I did not make use of the common Vitriolum Martis, which is easy to be had in the Shops of Chemists? I answer, That my design being to try whether or no I could obtain a Sulphur, that might properly enough (though not in the utmost rigour) we call Sulphur of Mars, that which is made the common way, would not answer my end, since though I should be able from this Vitriol to obtain a real Sulphur; yet I should not think it safe thence to conclude, that it came from the Metal, and not from the Menstruum; because I have several times from Oil of Vitriol itself, obtained no contemptible proportion of Yellow and Combustible Sulphur. To which I add, that the acquisition of a Metalline Sulphur, though it was not the only thing that I aimed at in this Preparation, for I presumed, that at least I should make a very great Comminution of the parts of Steel, which is one of the main things aimed at by the more Rational Physicians in the Preparations of that Metal.  
Upon these and the like grounds, I pitched upon good Spirit of Sea-Salt as a Menstruum, much fitter for my purpose than either Oil of Vitriol or the Acid part of Sulphur; and accordingly in a good many Ounces of this Menstruum, we dissolved as much as we easily could of choice Filings of fine Steel, and having filtered the Green Solution, we very slowly Evaporated it in a Glass Vessel, and took such care not to spoil the matter, that we had store of fine Green Crystals that were not very small, and looked prettily; most of these we put into a strong, but small Retort, and by degrees of Fire, and a strong one, for the last hours; we obtained divers Ounces of a Liquor that came over in white Fumes, like Mists driven by the Wind, and afforded a Sulphureous Smell: This Liquor we rectified, and had a Yellow Ponderous Spirit, that seemed to be much more of Kin to the Spirit of Sea-Salt, than to the common Oil of Vitriol; especially since being mixed with Aquafortis, it would, like Spirit of Salt, make it a Menstruum, that would even in the Cold Dissolve Gold in thin Leaves. Which last words I add, because having put into a little of it already made Yellow, by having dissolved Leaf-Gold a very thin Plate, but a pretty deal thicker than a Leaf of Hammered Gold, the Menstruum made it look all over white, almost like Silver, which seemed to argue, that this Vitriolate Menstruum differed from common Spirit of Salt. And however, it may be worth taking notice of by the By, that not only Vitriols Blue, as is well known to Chemists, but that Vitriols of one of those Colours, and whereof the same Metal is the basest, may differ much from one another on the score of the various, and to us perhaps, unknown Menstruum that dissolves the Metal, since our Green Vitriol yields Liquors very different from common English Vitriol of Mars made with Oil of Vitriol, though all the three be green. Which may give us some Reason of the uncertainty, whereof Vitriol is mainly employed; and 'tis perhaps worth remarking, that though we did not find the Vitriol of Mars made the common way, nor even Roman Vitriol to dissolve in a Vinous Spirit totally Inflammable, yet it would easily enough Dissolve our Saline Vitriol, (if I may so call it) which Solution to hint that in Transitu, you may perhaps see cause to employ as a Medicine in several Cases, and particularly as a Styptic in Wounds, since its Taste is very Astringent, its Parts very Subti, and made fit by the Vinous Spirit, to prevent Corruption; especially in those Climates where Surgeons complain. That they can scarce prevent the Breeding of Worms in Wounds, unless they do betimes Dress them with Spir. of Wine or Brandy.  
But that which we chiefly aimed at in this Operation, was the dry part, of what was Elevated by the force of the Fire. This we found to be distinguishable, partly by its Situation, and partly by more durable Accidents, into three kinds of Substance, whereof one was almost like a Powder, which after the Contact of Air, did in a while come over to be of a Yellow Colour, almost like Sulphur, but it was not indeed truly Combustible Sulphur. The other Substance consisted of larger parts, and was of a deep Colour, between Read and Brown. But the third, which seemed the most Copious of all, was made up of fine parts, larger than the former, of a deep Reddish Colour, and adorned with a fine Gloss, like that of Scales of Fishes, that looked very prettily.  
The Caput Mortuum was found to be of a Texture that would have surprised most Men; for a great part of it appeared to be turned into a Talky Substance, consisting of pretty broad and very thin Plates, smooth and glossy, that lay upon, and against one another, like those that make up Muscovia-Glass, when the pieces are more thick than large.     

CHAP. V.  
CONTAINING Experiments and Observations Solitary; in two Pentades.  

The I. PENTADE.  

EXPERIMENT I. A notable Comminution of Gold into Powder that will sink in Water.  
TO manifest into how great a multitude of Corpuscles, gross and heavy enough to sink to the bottom even of a Saline Liquor in the form of Precipitate or Powder; I thought of this Expedient. We took a Grain of Refined Gold, and having dissolved it without heat in a competent quantity of good Aqua Regia, we put to it by guess about two Spoonfuls of Water, and then by a Thread we hung in the mixture a little bit of clean metaline Body, and kept it suspended in the Liquor for many hours (or some few days.) By this means we obtained, as we expected, a Precipitate of a fine and deep Colour, so copious and so light, that it was a long time before it would all settle at the bottom. Then looking upon the remaining part of the Suspended Metaline Body, we found it so very little less than when the whole was first put in, that the diminution of it was not judged to amount to near a Grain. By which Experiment it appeared, that one Grain of Gold, not swimming in parts separately invisible, as 'tis in Solutions, but reduced to a Manifest Powder, seemed to make a considerable quantity of Precipitate at the bottom of the Cylindrical Vial, whose Diameter was about an Inch, that we kept it in. And this Glass being a little shaken, the Precipitate would rise like a Mud, and be so thoroughly dispersed in the form of a Powder, through the whole Body of the Liquor, and a greater quantity of Water added to it, that at first it would seem Opacous, and after some time, it would appear like a high and lovely Purple Solution. So that one Grain of Gold (for the Colour argued that there was some of that Metal, in every Corpuscle of the Precipitate) was reduced into as many Grains of Powder, as sufficed to lodge themselves in all the Particles of space great enough to be visible, that were contained in a Mass of sixteen Drachms (is Two Ounces) of Water.   

EXPERIMENT II. A Proof of the Metalline Nature of Granates.  
I have else where endeavoured to show that divers, if not most, of the real Virtues of some Gems, (for there are too many Fabulous ones ascribed to them) may in probability proceed from the Particles of Mineral Juices, that were admitted whilst the matter was yet in Solutis Principiis, or at least soft, and afterwards Coagulated with the Lapidescent part of the Stone. In confirmation of this Conjecture, I shall now observe, that having, upon some grounds not necessary to be here mentioned, suspected that Granates contain (some of them) besides some other Metalline Substances, divers Corpuscles of a Martial Nature; I made choice of some small ones, which by their deep and almost dark Colour, (to name no other Signs) I guessed to contain somewhat of Iron or Steel; and applied to them a pretty vigorous Loadstone, which as I expected, readily took them up and to which they constantly stuck afterward, till I forcibly separated them from it. But though I tried this upon more parcels of Garnets' than one or two, yet I found that there was not many in one heap, that would easily adhere to the Magnet.   

EXPERIMENT III.  
A Gentleman Eminent for his Travels into Eastern Parts, and for his Skill in Jewels, told me, in Confirmation of my Opinion about the Origine of Gems from Fluid Materials; that he had seen a white Saphir that was a Table-Stone, as they speak, i. e. flat and not cut in Facets, about the middle of which there was a Cavity about the bigness of a large Pins head, or small Fitch, that contained in it a drop of Liquor that it seems could not be Coagulated into Stone with the rest of the Matter: Which Liquor, he said, was very easily discernible by its shifting places in the Cavity, when the Stone was put into differing Postures. And when I asked, whether there was no Flaw or Commissure in the Stone, at which the Liquor may be suspected to have got in; he assured me that there was none, but that the Cavity was every way encompassed by the solid Stone, and was about the thickness of three Barley Corns beneath the upper Superficies of it.   

SCHOLIUM.  
It may be here fit to give notice once for all, about the Experiments that are in the following Collections, styled Solitary, that though most of them are delivered nakedly as matters of Fact, without any such Introduction or subsequent Reflection, as may be met with sometimes expressly, and oftener by Intimation in divers others; yet that it should not be thence inferred, either those that are simply recited, were lighted on by chance, or made at all adventures, or that they are of no use, because for the most part there is not any expressly ascribed to them: For as they were not written without a particular occasion and scope too, so that many of them may be applied to good purposes, will, perchance, be found here and there in our other Writings. And to make it probable in general, that most of them may not be useless, it may perhaps suffice that we refer to what we have elsewhere purposely Discoursed, about the uses of Experiments (even) to Speculative Philosophy.  
This may pass for a general Scholium applicable to most of those Experiments that are not attended with any particular Scholium, nor any thing in the Experiment or Observation its self, that may easily by an attentive Reader, be made to supply the place of a Scholium. Which last clause I add, to intimate, that besides my haste, another reason why so many Scholium's, as may be expected in the following Collection, will not be found in it, was, because the proemial part did, on several occasions, make it needless to subjoin Annotations.   

EXPERIMENT IU.  
An Ingenious and Credible Person (Mr. W.) assured me, that in one of the fine Gardens near Genoa, that he delighted to Visit, there was Pond, which being made on the side of a Hill, the Wall next the bottom of the Hill was so high, that Men could not look over it into the Pond, nor be at all seen over it by the Fishes in the Pond; and yet he has several times observed these Fishes to be called together by the Gardener, as he pleased, with a certain noise that the Gardener made to assemble them, though neither he nor any man else could be discovered by the Fishes that readily obeyed their Summons.  
This Relation may be of use in the Controversy, Whether Fishes hear under Water.   

EXPERIMENT V.  
Upon occasion of what is elsewhere said of the Production of vivid apparent Colours by the breaking of the beams of Light, on Corpuscles extraordinary Minute, though solid; I took a Globe of rock Crystal, which being for a certain use saw'n in two by a Cutter of Gems, and having looked upon the flat Surfaces, observed to the Sun Beams, the little Particles that (notwithstanding their seeming smoothness in the Shade) asperated their Surfaces, did so retract and reflect the Light, as to make them exceed the vivid Colours of the Rainbow, (but in a somewhat interrupted manner) sometimes on one part of the Surface, sometimes on another, as the Surface happened to be Situated in reference to the Sun.  
And having caused a choice and fine Grained Touchstone to be likewise saw'n asunder by the same Artificer, to make two of it; I observed upon the new Surfaces made by this Action, that to the Touch smooth and polished, such vivid Colours as I lately mentioned to be these Surface, were put in to various Position in reference to the Sun and the Eye; so that notwithstanding the great transparency of the Crystal and great Opacity of the Touchstone, their superficial Corpuscles were found fit to exhibit (in due positions) the vivid Colours we admire in the Rainbow.    

The TWO PENTADE.  

EXPERIMENT I.  
Having for less than two hours borrowed an Oculus Munai, whose Colour 
10 Cent. 12.  was White, whose Figure was Round and plain Convex, and whose Diameter, I judged, to be about a third part of an Inch (rather less than more) I put it into a very shallow Glass Vessel almost filled with fair Water, and observed within one Minute, or thereabout, with the Minute-Watch, that one part of the Edge began to appear somewhat Diaphanous, and the whole Stone did by degrees lose its Whiteness, appearing of a dark Brownish Colour: When this Change had reached the whole Surface, I looked upon my Watch, and found that the Stone had lain nine Minutes in the Water; out of which having taken it, I perceived the Body was grown Semi-Diaphanous, and the parts near the Edge being less thick, appeared to have lost much more of their former Opacity than the innermost part had. Then putting the Stone presently into the Water again, I let it lie there so long till the Time effluxed, since the beginning of the Experiment amounted just to half an Hour. Then taking it out, and wiping it, I found it was grown much more clear, since being held against the light, it looked almost like Yellow Amber, but not quito so Diaphanous. Then I exposed it to the Contact of the Air, in the Scales of a very good Balance (where it weighed four Grains and about a quarter) and left it for a quarter, or near half an Hour, in that Balance to try if by the recess of any imbibed aqueous Moisture it would become lighter; but want of Time hindered me from completing the Experiment, but did not deter me from making another Observation, which was, that within about a single Minute of an Hour, a portion of the Stone near one part of the Edge, was manifestly grown Opacous and Whitish, and within not many Minutes after, the whole Stone began to appear in a changing condition, but did not change in every part at once, nor did the alteration make an uniform Progression; but here one might successively discover divers white Arches, or as 'twere Zones, that were parallel enough to one another, and being quite Opacous, intercepted between them other little Zones, which being yet Semi-opacous, appeared of a Brown Colour, and concurred to make the Stone look like a very pretty Agate, wherein the Whiteness made a continued Progress as long as the Time permitted me to observe it: And the Possessor assured me, that within an Hour or or two it would be all of a Cream White (as he expressed himself) which I thought the more Credible, because I saw one part of it, that was pretty broad, to have obtained already a Whiteness, little, if at all inferior to that of Ivory.   

EXPERIMENT II. Remarkable Observations about Hurricanes.  
The late Governor of the Bermudas Islands, (very much subject to Hurricanes) in Answer to my Questions, about the Presages of those hideous Tempests, informed me, that these were of the principal Forerunners. First, That the Sea would manifestly swell at some distance from the Shores, insomuch, that the Fishermen would divers times make to Land, and warn the Inhabitants, upon the confidence of that Presage, to provide against that dismal Storm, though the Sea were then smooth enough. Secondly, That the Sea would beat with great Noise against the Shore, especially the Rocks, though there appeared no manifest Cause, as upon the account of the Wind or Tide, why it should do so. And this Sign would sometimes not appear till many Hours, or perhaps a full Day after that forementioned. And sometimes 'twas observed, that the Sea would now and then suddenly Invade the Shore, and gain further upon it than could be accounted for by the Wind or Tide, and then quickly Ebb away beyond the usual Low water-Mark, and after return again with more fury, and fall back further than before. Thirdly, That sometimes there would be perceived an ungrateful Smell in the Air, before the Hurricane began to Blow. And Fourthly and Lastly, My Relator affirmed to me, both he and others had seen many Bundles, as it were of long Streaks of differing Colours, some Whitish, some Reddish, and some Bluish, or Greenish, which by reason of their Figure are usually called in those parts Horse-Tails: And these were seen in parts of the Sky, where the Air was Troubled indeed, but yet no formed Clouds did appear to the Eye.   

EXPERIMENT. III. A Monstrous Pearl.  
Yesterday a curious Person came to show me a Monstrous Pearl, if I may 
Decemb. 23.  so call it, because it was very irregularly shaped, and of an Enormous bigness. For though it were so artificially set in Gold, that by the help of a little of that Metal fitly placed here and there, the whole Jewel represented a Lion; yet I made shift to Measure it exactly enough with a Pair of Calapar Compasses, (as they call those whose Legs are made Arch-wise) and found the Length to be just an Inch and an Half, and the greatest Breadth (where yet it was of a proportionate Thickness) to be 2/10 or 4/5 of an Inch. The Colour was Orient enough, all but one dark Spot, which by its size, figure, and situation, I guessed to be the remains of that Part (whether like an Umbilical Cord or no) whereby it was fastened to the Naker or Shell of the Fish that produced it.   

EXPERIMENT IU. An odd Observation about the Influence of the Moon.  
I know an Intelligent Person, that having by a very dangerous Fall, so broken his Head, that divers large Pieces of his Skull were taken out, as I could easily perceive by the wide Scars that still remain; Answered me, that for divers Months that he lay under the Surgeons Hands, he constantly observed, that about Full Moon, there would be extraordinary Prickings and Shootings in the wounded Parts of his Head, as if the meanings were stretched or pressed against the rugged Parts of the broken Skull, and this with so much pain, as would for 2 or 3 Nights hinder his Sleep, of which at all other times of the Moon he used to enjoy a competency. And this Gentleman added, that the Surgeons, (for he had 3 or 4 at once) observed from Month to Month, as well as he, the Operation of the Full Moon upon his Head, informing him, that they then manifestly perceived an Expansion or Intumescence of his Brain; which appeared not at all at the New Moon; (for that I particularly asked) nor was he then obnoxious to the forementioned Pricking pains.   

EXPERIMENT. V. An uncommon Experiment about Heat and Cold.  
To confirm what we have elsewhere delivered about the Mechanical 
Nou. 9 89.  Origine of Heat and Cold, we devised the following Experiment: We took a small and hermetically sealed Thermoscope, whose Stem was divided into parts, equal enough as to Sense, by little Specks of Amel, that sharp Liquors might not eat off or spoil the Marks. The Ball of this Instrument we put into a slender Cylindrical Vessel, (called in the Shops a Mustard Glass) and more than covered it with strong Oil of 🜖, and left it there awhile to be reduced to the temper of the surrounding▪ Liquor. Then we cast upon it by degrees, grossly Powdered, * which presently was wrought on furiously by the Menstruum; and by this Conflict, was produced a seeming Effervescence, with great noise and store of Froth, which more than once was ready to run out of the Vessel. But for all this seeming Ebullition, the mixture instead of growing Hot, did really grow Colder and Colder, as appeared not only when the Vessel was touched by the Fingers on the outside, but by a surer mark, which was the descent of the coloured Spirit of Wine. How much farther it would have descended, (for the Liquor was not near satiated with the 🜔) we were hindered from Discovering by an unlucky Accident, that broke the Thermometer, and put an end to that First part of our Experiment. But this was no hindrance to the Second part, which for its Novelty we mainly designed. For when we poured this actually and considerably Cold Mixture into three or four times its weight (by guess) of as much common Water, that was likewise actually Cold; this Second Mixture did, as I expected, immediately grow so Hot, that I did not like to keep my Finger for a Minute or two upon the outside of the Glass.     

An Advertisement about the Nature and Scope of the Chemical Experiments contained in the following Pentades.  
CHAP. V.  
Containing two Pentades of Chemical Experiments.  
BEfore you enter upon the perusal of the following Pentades, I think myself obliged to give you notice, that you will be deceived if you expect to find them consist, either Solely or Mainly, of Spagirical Secrets, or difficult and elaborate Processes. I do not indeed deny, that I am not altogether unfurnished with such as in probability, most Readers would refer to Experiments of that Nature, and you may find divers of them scattered upon fit occasions, in several of my Writings: But in the present Tract, though I have not forborn to mention here and there as many Particulars of that sort, as I thought necessary to excite and maintain the Curiosity, and sustain the Attention of a Reader that Relishes nothing that is not Seasoned with somewhat that is not common; yet in this Treatise, wherein I aimed not to appear a Chemist, so much as to make my Reader a Naturalist; it was more suitable to my design, though not more conducive to my Credit, that the following Pentades (which God permitting, may in tract of time, much increase in Number) should mainly consist of Experiments, rather useful than Specious; my design being to contribute some sound Materials towards the Erection of a solid and useful Natural Philosophy. In making choice of which Materials, I usually prefer those Experiments that afford the more Light to those that appear with the most Luster, and those that are proper to increase the Readers skill, to those that make an Ostentation of the Writers. On which ground it is, that, whatever I may do, where I purposely Recommend Chemistry, I make this small Collection, consist mainly of simple and not Intricate or elaborate Experiments. Those that are Simple being not only more easy to be Tried, and if need be, Reiterated without much trouble, or danger of erring; but (which I more regard) more easy to be judged of, as to their Causes, Phenomena and effects, and consequently more fit to ground Notions and Reasonings upon: Divers of which may probably in the applications that sagacious Persons may make of them, prove to be of Practical as well as Theorical use. Thus though a Wedg of Gold and a Diamond be, one more Rich and finely Coloured, and the other more precious and sparkling than a piece of Steel and a Hint; yet on many occasions the two latter are far more serviceable to Mankind than the former: Since not those that are more prized for themselves, but those that in comparison seem despicable, afford Sparks, which do not only give Light, but are fit to kindle Fires, which both afford incomparably more Light, and in the application are of excellent and necessary use in the Kitchens of Families, the Forges of Smiths of all sorts, the Furnaces of Mine-men, and the Laboratories of Chemists.  

The I. PENTADE.  

EXPERIMENT I. To Dissolve Crude Gold with dry Bodies.  
Because the generality of Chemists make so great a matter of Aurum Potabile, though they cannot deny, but that by their Preparations it is not made irreducible; and because also I am willing to grant, that even some Preparations, that leave the Metal reducible, may yet be of considerable use in Physic (the grounds of which Opinion I elsewhere declare, and shall not here repeat) I will in this place set down a Process, which though I do not overmuch value, served me well enough on some occasions, to Vye with those that much vaunted their particular ways (as they thought them) of making Aurum Potabile, I told them, I could make one in an hour or two's time without a Furnace; and that without any other Distilled Liquor whatsoever than common Spirit of of Wine well Dephlegmed.  
This I did several times, after the following manner. I prepared a Saline Mixture consisting of one part of Sal Almonia●, two parts of Roch Alum, and four parts of pure Nitre. This being well pulverised and mingled, I rubbed diligently in a Glass or Marble Mortar, with 15 or 16 parts in weight of the whole Mixture of Leaves of Gold, such as Apothecaries and Bookbinders use. Then I put this into a small new Crucible, and putting a few, and but a few, kindled Coals round about it, and at a little distance from it, to neal the Vessel; I soon after approached them, till the heat made the Matter melt, and so with that gentle Fire, I kept it in fusion, till it visibly emitted no more Fumes but grew dry again.  
This sign appearing, I presently took it off from the Fire, and whiles it was yet warm, dug it out, as clean as I could, and having seasonably pulverised it, that it might not attract the Moisture of the Air; I put upon it some highly rectified Spirit of Wine, which within an hour or less time, was ennobled with a rich Golden Colour. And accordingly I found it to be a real Solution of Gold, by divers Trials that I purposely made, to evince it to be so.  
Of this and some other less common Preparations of ☉ more may be met with hereafter.   

EXPERIMENT. II. Luna Cornea by Distillation.  
There was taken ℥ III of well refined Silver, thinly Laminated, and six of common Sublimate. This was put first into a Retort, and the Silver cut into small pieces, was put in after, that the matter lying uppermost might be Penetrated by the ascending Fumes: But the Fire having not been made strong enough, the Sublimate was Elevated to the uppermost part of the Retort, and left the Silver scarce at all changed in the bottom of the Glass. Wherefore we put the same Sublimate and Metal into another Retort, and administering a stronger Fire, that the Sublimate might be thoroughly melted before it could flee away, we obtained no running Mercury at all, but the greatest part of the Sublimate was Elevated in its usual form, leaving behind it the Silver in a Lump, which stuck hard to the bottom of the Glass, and appeared much altered. For besides that there was acquired ℥ I. in weight, many of the pieces of Metal stuck together, and seemed at least half Melted, and were of a kind of Horny and Semi-Diaphanous Substance, which would readily enough Melt almost like Sealing-Wax, when I held it to the Flame of a Candle, at which yet I could not perceive it manifestly to take Fire.   

SCHOLIUM.  
'Tis here to be noted once for all, that in this and divers other Chemical Experiments, there is sometimes much more delivered than is necessary to make good the Title, or the thing mainly intended. But 'twas thought fit, not to Dismember or Mutilate the entire Memoir as 'twas registered, because that of the other Particulars some may be, though indirectly, referred to the principal part, and others may be looked on as Phaenomena, which may be of use at least to me, by keeping me from forgetting them, and probably tend to the main design of all these Experiments, viz. to contribute to a Natural History, which may respect Practice, as well as Theory.   

EXPERIMENT. III. Mercury growing warm with Silver.  
We took ʒII of animated (or antimonial) Quicksilver, and put it into the palm of ones Hand; we put to it by degrees a Dram and an Half of Powder of fine Silver, made by Precipitation with Copper the ordinary way (but with more than ordinary care). Whilst this Mixture was making with one's Finger, he that held it in his hand, confessed he found it grow sensibly Warm; and I, whose Finger was considerably Warm, could not with it perceive any coldness in the Amalgame. This in a very short time became of a soft, and (as to sense) uniform consistence, and so soft that it was like almost melted Butter, insomuch that we added half a Dram more of the Calx of Silver, without rendering the Amalgame at all too stiff; and perhaps we might have added the other half Dram, without overcharging that penetrant Mercury: in which case it had swallowed up full its own weight of Silver; so different it was from common Mercury; and when we left off, it had reduced into a very yielding form, three quarters of its own weight of solid Metal. This aaa we put into a small Vyal, and stopped the Glass with a Cork, to observe whether the Amalgame would harden without intercourse with the free Air. Next morning it appeared to be concreted in the Glass; and the next morning after that, we broke the Glass to take out the Matter, which we found considerably hard, but brittle enough.   

EXPERIMENT. IV. The Durableness of the Faculty of a certain prepared Mercury to grow Hot with Gold.  
To convince those that Treat the Incalescense of Prepared Mercury and of Gold, as a Chemical Chimaera; I sent in a Concealed way to the Royal Society, some Mercury laboriously Prepared in my Furnaces, whereof ℥ I. being put upon a due proportion of a Calx of Gold made by the common way, (Quartation) they grew presently and very sensibly hot in the Palm of ones Hand. I shall now add, that to try whether this surprising Faculty of growing hot immediately upon Gold, will continue any long time in the Mercury; I lately took some that I had (for a certain purpose) kept Hermetically sealed in a Glass Egg for divers Years, (if I mistake not, Ten or Twelve at least) and having Reiterated the forementioned Trial with it; first alone, and then in the presence of a Cultivator of Chemistry; it presently grew hot with the ☉ in the palm of the Hand. And having Distilled off the Mercury, and tried it again as well as some that was Undistilled, if I much misremember not, it did again heat with the Gold.   

EXPERIMENT. V. An uncommon way of operating upon ♁.  
When Chemists expose Antimony, for instance, and divers other Consistent, but not fixed Bodies, to the action of the Fire, they are wont to do it in Vessels, either open, as when they make Calx, or Glass of Antimony, or at least in Vessels that are not so close: But that there is Air included with the matter, as when they Sublime it in Glasses, or in Earthen subliming Pots; and though they regard not this included Air, because usually there is not much of it in the Vessel, yet it may have a not inconsiderable influence on the effects of the Fires Operation, not only as it contributes to the ascension and sustentation of dissipated parts of the Mineral, but as it affords these Corpuscles room to fly to and fro in it, and thereby make Associations or Coalitions and Concretions that otherwise would not be produced. Upon this account I guest that it may be, on divers occasions, a thing of use for Discoveries, and perhaps too, for Practice, to employ a Method, that the Body exposed to the action of the Fire, may be kept from the Contact of the Air, at least as to any sensible portions of it, and being as it were included in Bodies almost equivalent to Solids; and one may suppress the free emission and ascent of Exhalations, and so to make an Operation, not only in Clauso, but as it were in Solido, and reduce the parts of the Body Exposed, and perhaps the Igneous Corpuscles to act reciprocally upon one another, without any notable Dissipation, or Avolation of Parts.  
To apply now what hath been said, to Antimony; I shall briefly set down an uncommon way that came into my mind of Operating upon it. We took well powdered ♁, and well dried (white) Chalk reduced likewise to Powder; with these in a large Earthen Pot or Crucible, we made SSS. having a care to make the lowermost and uppermost bed of Chalk, and the last thicker than any of the rest, as also that none of the Antimo-nial Layers, were but of a moderate thickness, that the Heat might penetrate them the better; then the Vessel, being covered, was put among the kindled Coals of a good digestive Furnace, (not because such a one was necessary, but because 'twas at hand) where 'twas kept for a competent time, which according to the bigness of the Pot, and the strength of the Fire, may be sometimes 20 or 24 Hours, sometimes a Day and a Half, and sometimes two Days or better.    

The II. PENTADE.  

EXPERIMENT I. A very uncommon way of making a Cale of Gold.  
'Tis known that most Chemists, and many Physicians, have a Superlative Esteem for the Medicinal Virtues of Gold, and the Preparations of it. And upon this ground, divers of them have long been, and still are Solicitous to make Calces of Gold by differing ways; most of them laborious, and some of them scarce to be safely wrought and used in Physic: Wherefore I shall, I presume, be easily Pardoned, if I here set down a way that came into my mind, and that I have sometimes used to make a preparation wherein Gold is reduced to very minute Parts, without the help of Mercury, or of any Precipitation made by sharp Salts, whether Acid or Lixivial.  
We took then refined Gold, and dissolved it in clean and Spirituous Aqua Regia, and instead of Precipitating the clear Solution with Oil of Tartar per deliquium, as is usually done, or with Spirit of Sal Armoniac, or other Volatile Urinous Spirits, we first with a very modest Heat drew off the Superfluous Liquor; whereby the Gold with the remaining part of the Menstruum, was left in the appearance of a thick and Oleous Liquor. This done, we poured upon it a treble weight of Vinous Spirit totally inflammable and in a short time, we had, as we expected, a very subtle Powder, or high coloured Calx of Gold, that subsided at the bottom; the Menstruum being strangely dulcified as to Taste, and become fragrant in point of Smell When a very few days were passed, we decanted the Liquor, and put on it fresh ardent Spirit, and leaving them a while together, there subsided the like well coloured Calx more plentifully than the first time.  
I know not, to add that upon the by, whether it may, or may not be worth while to try to Discover whether this Dulcified A. R. Spirituosa being drawn off from the subsiding Gold, may have acquired any Virtue from the opened Metal. Some Trials seeming to argue that the openness of this Calx made it fit to be easily wrought upon by a Menstruum that would not touch Water-Gold, as they call the common Calx made by quartation, nor yet Leaf-Gold, such as the Apothecaries Employ; but however the Menstruum has acquired such qualities as make it seem likely to prove an useful Medicine, which yet I refer to Trial.  
By the way we pitched upon to make this Powder of Gold, it seemed probable, that it would not (at least) be less subtle, and yet would be more mild, than common Preparations; and nevertheless we thought it might, perhaps, make it yet more secure, if we should, as we did, put upon it a totally Ardent Vinous Spirit, and burn it off once, twice, or thrice, to carry off with it any little Corosive or Saline Particles▪ that may have still adhered to the Metalline ones.  
N. B. The Spirituous Aqua Regia, mentioned in the Process, is so called by me, partly to distinguish it from the common Aqua Regia, and partly because 'tis indeed of a more Spirituous Nature than the common, being composed without any gross Salt; Such as * but only of Spirits. This Menstruum I made for some particular uses: And though it works more slowly than the common Chrysulca, yet I often prefer it to this, as that which I can employ to some uncommon purposes, and as it may probably be a more innocent Menstruum in making Preparations of Sol, designed for Medicinal uses. I make it very easily, by mixing one part of good Spirit of Salt, with two parts of strong Spirit of Niter, or (when 'tis not to be used for Medicines) of common, but clean Aqua Fortis.   

SCHOLIUM.  
The above recited Trial was made as 'tis delivered; but some Circumstances that I took notice of, and particularly some Grains of Powder that, though mingled with the rest, were shining, as if they had been extremely Minute, and bright Filings of Gold. These Circumstances, I say, made me Suspect that the Success might much depend upon particular and nice Circumstances that may need more exact Trial, than I had then occasion to make; and therefore it may be fit that the Experiment be heedfully repeated. It may also be tried whether the employing common A. R. instead of the Spirituous, will much vary the Experiment.   

EXPERIMENT II.  
To try how much Volatile Salt an assigned quantity of Water would Dissolve, we took ℥ III of Distilled Water, and put into it by degrees, some dry Salt of Salt Armoniac (that was very White, and compact enough) keeping the Liquor in digestion for a pretty while, that it might have time to Dissolve as much as it could. When we found it would Dissolve no more in a moderate Heat, we took it off, and found that after standing some Hours in the Cold there fell to the lower part of the Glass, and settled there, a pretty quantity of Salt, which we guessed to be about ʒII, which being deducted from ℥ TWO, that had been in all put in, there remained ℥ I and ʒVI in the Liquor, which by this account had Dissolved at least half its weight of Salt.   

SCHOLIUM.  
I desire it may not be thought strange, if among our Chemical Experiments, some few shall be here and there met with, that are much less Elaborate or Promising than others that I could easily have inserted in their Rooms; for I did it on set purpose, partly because oftentimes (as was intimated at the beginning of the Chapter) some more simple or seemingly less valuable Experiments may be fitter materials, than more curious ones, for the Natural History we would promote; and partly to give an Example, if mine can signify any thing, of not disdaining to Register some things that seem mean; if by the light they afford, or the uses they may be applied to, they compensate the want of Lustre, and of immediate Utility. And the substance of this Scholium I desire may be mentally transferred, as occasion shall require, to those following Chapters that Treat of Chemical Experiments.   

EXPERIMENT. III.  
Perhaps some Chemists will think that the following Memoir may give hints that may be of use on several occasions, both for other purposes, and for theirs, that would draw Tinctures from several Bodies, that will not afford them in simple Spirit of Wine, though well rectified.  
The simple Spirit of good French Verdigreas, being once or twice abstracted from as much Salt of Tartar as it would dissolve in the Cold; left the Salt easily susible, and dissoluble in highly rectified Spirit of Wine.   

EXPERIMENT IU.  
I have not been unacquainted with some Curious and Elaborate Preparations of that noble Flower the Rose; and experience hath convinced me that 'tis possible, whatever most Chemists think of it, to obtain from Roses a true essential Oil, that mixes not with Water, and is exceeding fragrant: But there are several that are so far from believing that an Essential Oil may be obtained from Roses, without being in the form of a Butter, but in a liquid one like Oil of Cloves, or Wormwood, that they doubt whether a true Spiritus Arden's can be obtained from them, without addition of Wine, or some such inflammable Liquor. I shall here transcribe the following Note, as containing a more simple and easy Preparation (than any of those before mentioned) of the Ardent Spirit of those Flowers, and therefore more suitable to the design of the whole Chapter.   

To make an inflammable Spirit of Roses.  
Two Bushels of Damask Roses (together with a good number of red Rosebuds) being beaten, and put into a Vessel with Water amounting to about 4 Gallons, were mingled with about a quart of Ale-Yest, and kept in Fermentation for about 5 or 6 days (the weather being cold for the Season) and then being Distilled per vesicam, afforded us a Spiritus Arden's.   

EXPERIMENT. V. An Experiment about the Chemical Analysis of Pearls.  
We took ℥ TWO of Seed Pearl, that were carefully bought for Oriental, and without breaking them, put them into a Retort, and Distilled them in a Sand-Furnace by degrees of Fire, giving a strong one at the last. By this means we had a little Black Oil Swimming upon the Spirit, which was also dark and muddy, as if incorporated with some more Oil. The weight of both these Liquors was 23 Grains, besides which there stuck to almost all the upper part of the Retort, a thin film of Oil, which together with a streak of the like reaching to the bottom of the Receiver, we estimated at 3 Grains more, and so reckoned 26 Grains for the weight of the whole ascended matter. The Caput Mortuum amounted to full the remainng weight of two Ounces. The Empyreumatical Liquors that came over, smelled much like those of Hartshorn, and the Spirit was found to belong, as we expected, to the Tribe of Urinous ones, or, as many now call them Volatile Alcaly's For it readily hissed and produced Bubbles, with good Spirit of Salt turned Syrup of Violets Green, and being dropped into Solution of Sublimate, turned that White; to omit another way or two, by which I examined it. The Oil that stuck to the Retort, and which was fetid, like that of Hartshorn, did easily dissolve in dephlegmed Spirit of Wine, and afforded a reddish Brown Solution. The Caput Mortuum was very black, and some Grains of it were found readily enough dissoluble in Spirit of Vinegar. Being calcined in a well covered Crucible, with a strong Fire (for a moderate one will not do it, unless it be long) we reduced them to be purely White, and to a weight less by some Grains than an Ounce, and ʒIII and we found, as we expected, that being Pulverised, this Calx tasted hot and bitterish upon the Tongue, like good Calx Vive, and was not only of an Alcalisate, but a Lixival Nature: For besides that it presently turned Syrup of Violets Green, it quickly afforded an Orange Coloured Precipitate, with Solution of Sublimate.      

Strange Reports, In II. PARTS.  
Addressed to a Vertuoso, Friend to the Author.   

Advertisement.  
I Presume, Sir, you may yet remember, what I Wrote about the Nature and Scope of my Collection of Strange Reports, in an Essay which takes its Title from them; and which I was encouraged to make by the Example and Authority of Aristotle. And therefore 
This Famous Philosopher in his little Tract, whose Title some tender de Mirandis Auditionibus, scrupled not to comprise without Method, divers Reports, uncertain or fabulous, nor to insert several that were not so cautiously admitted as those recited in the following. Collection.  I shall desire, that to save your Trouble and my own, That Paper may serve for a Preface to that which follows. About which, supposing this Request to be Granted, I shall need to give you at present but this short Advertisement; That for distinction's sake, I thought fit to divide the ensuing Particulars into two Parts, because they are indeed of two sorts: One relating to things purely Natural, and the other consisting of Phaenomena, that are, of seem to be, of a Supernatural Kind or Order.  
The first Set of Particulars belonging to each of the two forementioned Parts, has prefixed to it the Title of the First Section, though it be not at this time attended by a Second; because 'tis designed, that God permitting, it shall be so hereafter, when I shall get time to pick up out of my Adversaria, and other Memoirs, Particulars fit to have placed in the List of Strange Reports.  
I must likewise give you notice, That you are not to expect the II. Part at this time: Discretion forbidding me to let that appear, till I see what Entertainment will be given to the I. Part, that consists but of Relations far less strange than those that make up the other Part.   

Strange Reports. PART. I.  

SECTION. I.  
RElating to a judicious Virtuoso, that a Physician of Brussels a while since affirmed to me, That he himself had prepared 3 or 4 resuscitable Plants, one of which he had presented to the Marquis of castle Rodrigo, now Governor of the Spanish Netherlands, where this Virtuoso had not long since been. Relating this, I say, to this Gentleman, and Enquiring of him, whether he had seen this resuscitable Plant; he answered me, That he had never seen nor heard of it; but told me on this occasion, That coming to Deal with an Apothecary of Namier, if I misremember not the Name, much esteemed for his extraordinary Skill in Chemistry about some choice Preparations, wherewith this Man's Shop was furnished the Apothecary told the Virtuoso, that he had really prepared resufcitable Plants, a different way from that which others pretended to, and that he could prepare a great variety of them. And when having enquired of the Virtuoso, whether he himself had seen any of these prepared Plants, he assured me, that he had seen not only some, but many; I then upon farther enquiry how they appeared, learned that the Chemist had divers of them in distinct Glass-Bottles; that the Apparitions that were exhibited, showed not the peculiar Colours, but only the shape of the Plant; but this so genuinely that he could perfectly distinguish and easily know it to be such or such a Plant instancing particularly in Carduus Benedictus, and Camomile.  
And the difference betwixt this way of Exhibiting Plants, and that which is mentioned by Quercetan, and pretended to by others; I found by this Gentleman's Answers, to consist chiefly in these two things: The first, that the Apothecary's Plants did not as the others seem to grow up into the Air included in a Sealed Vial, but were seen as growing in a clear Liquor, wherewith the Bottle that contained it was almost filled; and the next, That whereas to make the Apparition, mentioned by Quercetan, and others, the Application of an actual Heat (as that of a Lamp, or the Sunbeams, or the like) is affirmed to be requisite, upon the absence of which the Fantastical Plant relapses into its Ashes. In the formation of the Apothecary's Vegetables, he doth not employ any actual Heat, but (which may seem more strange) only the shaking, of the Bottle, for upon that Agitation the prepared Ashes or Powder being thised from the bottom, and dispersed quite through the Liquor, when the Glass is set by in a quiet place, the scattered Particles by degrees so convene, as to compose a Model of the Plant they once belonged to. And Heat not being requisite to their formation, these Plants do not quickly, as the Pelonian Physician's Fantastic Vegetable, Recorded by Quercetan, fall back into a Powder; but if let alone, continued a great while, until the Preparer think fit by a gentle Agitation of the Bottle, to dissolve the loose Contexture of it.   

RELATION II.  
I met the other day with a very intelligent Person, well versed in Chemistry, not credulous, and in a word very well worthy of Credit, who assured me, that he had himself seen a few years ago at Mentz, in the Hands of one Monsieur P— r, a Gentleman of Switzer-land, and a Virtuoso, a piece of Glass about the bigness of a Shilling, or somewhat bigger; which was Red and pretty transparent like Glass of Antimony made per se, and which this Monsieur P. affirmed to the Relator, that he Hammered before the present Elector of Heidelberg (to whom I told him, I had the Honour to be known, and) by whom the Relator was about that time employed. And this Monsieur P. being his intimate Acquaintance, and perceiving that he was, (as he well might be) indisposed to believe so strange a thing, after he had confessed the Glass to have been given him by an excellent Chemist in his Country (Switzerland); this Gentleman, I say, at the Relators earnest Request, gave him leave for his satisfaction, to lay the piece of Glass upon an Anvil, and to strike seven or eight strokes with a Hammer upon it; by which means he found, that though it was nor malleable (at least in the state it then was) like nealed Silver, since it began to crack at the edges like Silver that is over-hammered; yet it did really stretch under the Hammer, growing more thin on the beaten part, and having visible Marks or Impressions made on it by the edge of the Hammer.   

RELATION III.  
A Pious and Learned Schoolmaster, that ventured to stay in London in the great Plague 1665, and was much Employed, as some Friends of mine that knew him, and commended him, assured me, to Visit the Sick, and distribute Alms and Relief to them, went indiscriminately to all sorts of Infected, and even Dying Persons, to the number, as he told me, of nine Hundred, or a Thousand; and being asked by me about the Infection of other things than Walls, he told me, That being once called to Administer some Ghostly comfort to a poor Woman that had Buried some Children of the Plague, he found the Room so little, that it scarce held any more than the Bed whereon she lay Sick, and an open Coffin wherein he saw her Husband lie Dead of the same Disease, whom the Wife soon after followed. In this little close Room they affirmed to him, that the Contagious Steams had produced Spots on the very Wall; and when I asked, whether he himself had seen them, he answered, That he had not; but yet was inclined to believe the thing to be true, not only upon the score of the Relators, but because he had observed the like in his own Study, which being divided only by a Wall from some Rooms of a House, which the Owner had turned into a kind of a Pest-house, and in which, Numbers had Died in a short time; he took notice that the white Wall of his Study was (since the Sickness raged, without any other cause that he could imagine) Blemished in divers places with Spots, like those of Infected Persons; when (to add that upon the by) I enquired what Antidote he used; he replied, That next the Protection of God, which so many sad Objects made him the more fervently Implore, and a constant fearlesness, the only Preservative he used, besides good Diet, were half a Spoonful, or a Spoonful of Brandy five or Six times a day, especially when he went into Infected places, and the bigness of a small Nut or less, of a Root of Spanish Angelica, of which he held in his Mouth the quantity of a Pepper-corn, or somewhat less, as often as he thought there was need.   

RELATION IU.  
An ingenious Person, 
January, 25.  and very worthy of Credit, informed me the other day, in answer to some questions that I proposed to him, That he was Employed some years ago by a Germane Physician (whose Name he told me) to Distil a certain Mineral not unknown to me, which he performed in a naked Fire, with so good success, that he had from about half a Pound of the Mineral, near ʒIII of the Liquor; this he included in a Glass with a Bubble, and a slender neck like one of my Weather-Glasses; but though the Liquor at first reached not above the Bubble, but only filled it to the bottom of the Pipe; yet as the Moon increased, this Liquor, as the Doctor expected, by degrees expanded itself in the Glass, so that about the Full- Moon, it reached about an Inch into the Pipe, and upon the Decrease of the Moon, it subsided by degrees to the bottom of the Pipe. And when I asked, whether the Vessel were carefully stopped, he answered, That it was not only so, but Hermetically Sealed like one of my Thermometers with Spirit of Wine, which he had seen. This the Relator averred to me upon his own Observation, and being desired, he readily gave me a description of the Mineral, and a direction where to procure it, (which I am now endeavouring to do) adding that the same Doctor made the like Trial with another Mineral, akin to this, with which my having heard that such an Experiment had been done, gave me occasion to propose him the question.   

RELATION V.  
An inquisitive Traveller that not long since waited on a Germane Prince addicted to Chemistry, and was employed by him in his private Laboratory; being asked by me some questions about Ore of Bismute or Tin-glass, whereof there is said to be a Mine in that Prince's Territories, and in particular, whether he had observed any thing of the varying bulk of a strange Liquor obtainable from it: He answered me to this effect, That he had had occasion to make many Trials upon this Mineral, and that particularly by his Prince's command, he had Distilled a considerable quantity of a certain sort of it (because it yields but very little Spirit) and that he thereby obtained a Liquor, which being by Rectification freed from its superfluous Phlegm, amounted to about half a Pint. This Liquor was put into a Vial, which it almost half filled. This Vial being exactly stopped, was set aside in a quiet place, where, (as the Prince expected) as the Light of the Moon increased, from the New- Moon towards the Full; so this Liquor gradually swelled, and that not in a hardly perceptible degree, but very manifestly and confiderably; so that when the Moon was Full, the Liquor reached almost to the top of the Glass, and during her Wane, as the Light decreased, so did the bulk of the Liquor, which was always lest at the New- Moon. I asked him if any Trial had been made, whether the Weight of this Spirit varied with the Bulk, and he frankly confessed to me, That it had not come into his Mind; but for what is above Related of the Increment and Decrement as to quantity affirmed to me, that he himself, as well as his Prince had several times Observed it; and he also readily told me the way he used in making the Distillation, which he said, exacted an intense degree of Fire.   

RELATION VI.  
An inquisitive Person, that having gone through his Studies in the University, Travelled through divers Countries to make himself the more fit for the Profession of Physic, answered me, That having Resided for some time in Prussia, he had more than once or twice (and that in differing places) observed, as others in his Company also did, That the Fishermen in breaking the Ice of long Frozen places, and taking out thence considerable Masses of Ice, did several times find in them Swallows, sometimes numerous enough, that were so enclosed in the Ice, that unless by breaking or thawing it, they could not be gotten out of it. And he further answered me, That when these Lumps or Masses of Ice came to be thawed in their Germane Stoves, the Swallows, that lay as Dead before, would Revive, and perhaps fly about the Room; but did not long survive their Recovery out of their Insensible state; some Dying again in few hours, others the next day, or perhaps the third; but sew or none, that he observed, Living beyond the fourth or the fifth; which immature Death, my Relator judged to be caused by their having no Appetite to Eat, which Inappetency made them Die Starved. But as the conjecture may be true as to those that Lived for some days, so it seems not like that those that Perished in few Hours, Died merely of Hunger; and as for them that were Starved to Death, I should suspect that they were Starved, not so much for want of Appetite, as for want of such Animals as they used to Feed on, especially Flies, which they could not get in Winter.   

RELATION VII.  
An Inquisitive Gentleman lately Returned from Jamaica, where he was Employed by the Governor to make Discoveries of Natural Things, answered me (this Morning) that he had seen in that Island great number of Trees that bear the Silken Cotten, that he found many of them to surpass in bigness and height the larger sort of our English Oaks; and that on a Mountain that many went to Visit out of Curiosity, to view a stupendious Silk-Cotton Tree, he saw its Bulk, and many affirmed to him, and it was the general Tradition of the Country, which he saw no cause to disbelieve, that this prodigious Tree was in the Body no less than 21 yards about, that is, more than 60 Foot in Compass.  
The same curious Traveller told me he saw a Cannow made of the hollowed Trunk of one of these Silk-Cotton Trees, which after all that had been taken off to give it the shape of a Vessel fit for Service, was 30 Foot about, and of at least a proportionable length.   

RELATION VIII.  
A Merchant Rich and Judicious, and more addicted to Letters than is usual to Men of his Calling, being returned into England, from some of the remoter Parts of the East-Indies, to satisfy my Curiosity about a strange Tradition of several Navigators about a more than one way extraordinary In-draught of the Sea on the Coast of a great Island of the Southern Ocean, sent me the ensuing Relation, which though it contains something manifestly Fabulous, but easily distinguishable from the rest, I give you in the Relators own Words, being unwilling to alter any thing till I can see him again, and propose my Scruples to him.  
At Campar and Rakan, on the East Coast of Sumatra, is in the River's Mouth (to a certain distance) at each New and Full-Moon, a Violent In-draught of the Sea, (called Bunna) which approacheth with an hideous noise, and Mountain-high, so that whatsoever opposeth it, Perisheth. It's approach is in three Parts, the first high, but not so terrible; the second is high, black and horrid; the third is low, and of gentle motion; before its approach, it giveth so fair warning, that the People may Eat, and bathe themselves, before they weigh Anchor; but when they weigh, they must Row hard against it, and when its fury is past, follow with it, till they return to their Anchor place. The true reason whereof the Inhabitants cannot discover: But (as if Greece only were not the Mother of Fabulous Traditions) these poor Natives Fabulize, That at Campar (where is the greatest Bunna) in former Ages, there was a Princess, who, to shun the Rape of an insolent Casfree Slave, ran into the Seas mouth; but the Slave still pursuing her, and after him the Princess' little-Dog; all perished and thus (by a new Metamorphosis) these three Waves perpetuate their Commemoration. That afterwards a bold Fellow hoping to divert this Bunna from Campar (by advice of some Wizards) Rowed up against that first part of the Torrent, and filling a Bottle of its Water, which he immediately stopped up close, he betook himself to Rakan (not far distant) and poured it out into that River's Mouth, which brought the Bunna thither also, though it left not Campar; but that Fellow suddenly after Dying, none durst since attempt the like, else the Natives fancy it may still be done.  
My humble Opinion is, (adds my Relator) that the Mouths of those Rivers being choked up with their Sand-Banks, and so rendered very Shallow; when the great spring-tidings come roaring over those Shoals (at the New and Full-Moons) out of the Malacca Streights, the first Influx is Irresistible, by such small Vessels as use that Port, (especially if attended with dark Wether or Stormy Gusts) so that they are forced to Weigh and Bear up against it for fear of being Strandded and Split. In which Sentiment I rest, till I can attain a more prevalent Reason.   

RELATION IX.  
A Gentleman that had Travelled far and Observed much, related to me, That being off the Coast of Mosambique, between the 20th and last Days of September, the Captain of the great Portugal Ship they were in, walking to and fro upon the Deck, Spied a great way off, a very little dark Cloud or blackish Spot in the Sky: Whereupon, though the Wether were fair, he made all the hast he possibly could to provide for a great Storm, by taking in the Sails, etc. And thó for a while the Sky continued clear, and they had no signs of an imminent Change; but that when the Cloud approached, the Wind that had till then filled, their Sails ceased, and the Sea became Calmer than before: But presently after they had a furious Hurricane, which turned their Ship quite round many times one after another, as if it were an Aerial Whirl-pool, which lasted for above two Hours, and then left them, seeming to have a progressive Motion, as Whirlpools in Rivers often have.   

RELATION X.  
An Ingenious Practitioner of Physic, accompanied by one of the same Profession, assured me with great Asseveration, That some while since, being at a place in the Country near Amsterdam, where there Lived a kind of a Farmer, who (though Illiterate enough) was reputed very Curious; this Person showed him, among other things, a considerable quantity of Quicksilver that was altogether of the Colour of Gold. And, to answer my scruple, this Relator added, that the Colour did not belong only to the Surface of the whole Mass; but having purposely (with Water) divided it into many Globules, each of them retained the same rich Colour. And he further told me, That the possessor of this yellow Mercury, having put some of it over a Fire in a convenient Vessel, it quickly lost its fludity, and was precipitated into a red Powder; about which he hoped to learn some notable things at his next Visit to the Author: But that having been too long delayed; when he came to the place again, he found to his great Grief that the Master was Dead, and his Relations were, or pretended to be, ignorant of his Secrets.  
A very Learned and Experienced Physician, made me a Visit to give me notice, that a few Days before he had received one in the Night from a couple of Strangers, one of whom by some things that he saw him do, he judged to be (what they call) an Adeptus, who besides a thing far more rare and valuable, showed him as a Curiosity, a running Mercury of a lovely Green. And when I asked my judicious Relator, whether he had broken the fluid Mass into Drops, to observe whether the Colour were that only of the Surface, or of the whole Mass? He answered, that he purposely laid it upon a rough Body, as a Carpet, and found the Globules, whereinto 'twas by this Means divided, to be of the same fine Green that had beautified the whole Mass.  
These Relations, though they had come to me from less Credible Persons than those I received them from, I should not hastily have rejected, because of some odd and fine Colorations of running Mercury, that I have myself Observed, but here forbear to mention, because they belong to another Paper.   
FINIS.