Thursday, Novemb. 15. 1677. At a Meeting of the Council of the Royal Society  
Ordered,  
That a Book, entitled Experiments in Consort of the Luctation arising from the Affusion of several Menstruums upon all kinds of Bodies, exhibited to the Royal Society, April 13. and June 1. 1676. by Nehemiah Grew, M. D. Fellow of the R. S. be printed by John Martin, Printer to the said Society.  
Thomas Henshaw Vicepraeses S. R.   

EXPERIMENTS IN CONSORT OF THE LUCTATION ARISING From the Affusion of several MENSTRUUMS Upon all sorts of Bodies. To which is added The Nature, Causes, and Power of Mixture. Exhibited to the Royal Society. By NEHEMIAH GREW, M. D. and Fellow of the Royal Society.  
LONDON, Printed for John Martin, Printer to the Royal Society, at the Bell in S. Paul's Churchyard. 1678.   

EXPERIMENTS IN CONSORT OF THE LUCTATION ARISING From the Affusion of several MENSTRUUMS Upon all sorts of BODIES, Exhibited to the Royal Society, April 13. and June 1. 1676. By NEHEMIAH GREW, M. D. and Fellow of the Royal Society.  
LONDON, Printed for John Martin, Printer to the Royal Society, at the Bell in S. Paul's Churchyard. 1678.   

TO THE MOST ILLUSTRIOUS THE ROYAL SOCIETY, THE FOLLOWING EXPERIMENTS ARE MOST HUMBLY PRESENTED BY THE AUTHOR NEHEMIAH GREW.   

THE PREFACE.  
THE intent of the following Experiments is twofold. The one, To be as a Demonstration of the Truth of one, amongst other Propositions, laid down in my Discourse of Mixture, sc. That it would be a Key to let us easily into the knowledge of the Nature of Bodies.  
The other, and that consequently, To be as a Specimen of a Natural History of the Materia Medica: that is to say, a multifarious Scrutiny into the intrinsic Properties of all those Materials, which have been, or may be used in Medicine: for the performance whereof, the following Method is exhibited as one, amongst others, necessary to be insisted upon. For what Dominion a Prince hath over the Moral, that a Physician hath, as one of God Almighty's Vice-Roys, over the Corporeal World. Whence therefore nothing can more import, than a particular knowledge of the Genius of all his Subjects, those several Tribes of Matter, supposed to be under his Command.  
The Experiments may seem too numerous to be of one make. But no less a number would have answered the design of an Universal Survey; which, though less pleasing, proves the more instructive in the end: not being like angling with a single Hook; but like casting a Net against a shoal; with assurance of drawing up something. Besides the advantage of comparing many together; which being thus joined, do oftentimes, like Figures, signify ten times more, than standing alone, they would have done.  
How far the Corollaries all along subjoined have made this good, is left to the Reader to judge. And also, to add to them, so many more, as he pleases; for I make my own thoughts no man's Measure. Those I have set down, if compared, will, I presume, appear easy and natural; which is all I shall say for them. Let them go and take their fortune without a Flambeau; which being prefixed to things of so glimmering a show, would not serve to blazon, but extinguish them.   
EXPERIMENTS IN CONSORT OF THE LUCTATION Arising upon the Mixture of Bodies.  

CHAP. I.  
ALthough there are some known Obervations of this nature; yet there is no Author, I think, who hath given us a Systeme of Experiments in consort upon the Subject: the performance whereof, therefore, is here intended.  
The Bodies whereupon I made trial, were of all kinds, Animal, Vegetable, and Mineral. Amongst Vegetables, such as these, scil. Date-stones, Ginger, Colocynthis, Pyrethrum, Hawthorn-stones, Staphisagria, Euphorbium, the Arenulae in Pears, Semen Milii Solis, Tartar, Spirit of Scurvygrass, Spirit of Wine, etc.  
Amongst Minerals, several sorts of Earth's, Stones, Oars, Metals, Sulphurs, and Salts.  
Amongst Animals; such as these, scil. Hairs, Hoofs, Horns, Shells and shelly Infects, Bones, Flesh, and the several Viscera, Silk, Blood, Whites and Yolks of Eggs, Sperma Ceti, Civet, Musk, Castor, Gall, Urine, Dungs, animal Salts and Stones.  
The Liquors which I poured hereupon severally, were these, scil. Spirit of Salt Armoniac, Sp. of Hartshorn, Sp. of Nitre, Aq. fortis, Oil of Salt, Oil of Sulphur, and Oil of Vitriol.  
In the mixture of these Bodies, two things, in general, are all along to be observed, viz.  
First, which they are, that make any, or no Luctation. For, as some which seem to promise it, make none: so, many, contrary to expectation, make a considerable one.  
Next, the manner wherein the Luctation is made; being with much variety in these five sensible effects.  
1. Bullition; when the Bodies mixed produce only a certain quantity of froth or bubbles.  
2. Elevation; when, like Paste in baking, or Barm in the working of Beer, they swell and huff up.  
3. Crepitation; when they make a kind of hissing and sometimes a crackling noise.  
4. Effervescence; then only and properly so called, when they produce some degree of heat.  
5. Exhalation; when not only fumes, but visible steams are produced.  
Of all these, sometimes one only happens, sometimes two or more are concomitant. Sometimes the Luctation begins presently upon mixture, and sometimes not till after some intermission. In some bodies, it continues a great while; in others, is almost instantaneous: Examples of all which I shall now produce; beginning with Vegetables, as affording the least variety.  
And first, if we take Spirit or Oil of Salt, Oil of Vitriol, Spirit of Nitre, or Aq. fortis, and pour them severally upon the several parts of Vegetables, as Roots, Woods, Stones, etc. we shall find, that they are, generally far less apt to make a Luctation, than either Animal, or subterraneal Bodies.  
Whence, as from one argument, it seemeth evident, That in most Vegetables, and in most of their parts, the predominant Salt is an Acid. But that, on the contrary, the predominant Salt in most Minerals, and parts of Animals, is an Alkaly: in the former, usually a fixed; in the latter, a volatile Alkaly.  
Again, although the Luctation which most Vegetables, and most of their parts make with Acids, be but small, yet some they make; especially with some Acids, as with Spirit of Nitre and Aqua fortis.  
Whence it seemeth plain, That there is an Alkalizate Salt existent in many Vegetables, even in their natural estate; and that it is not made Alkalizate, but only Lixivial, by the fire. Or, there is some quantity of a Salt, call it what we will, in the said Bodies, which is so far different from, as to make a Luctation with an Acid. But to give particular instances of the several proportions wherein it appears to be in several Vegetables.  
And first, of all vegetable Bodies, Date-stones are amongst the least apt to make a Luctation with Acids, if they may be said to make any at all.  
Hence they are not so potent Nephriticks, as many other Stones, which make a more sensible Luctation.  
Ginger makes a small Bullition with Aq. fortis, only observable by a Glass.  
Hence the pungency of Ginger lieth in a sulphureous and volatile Salt, which yet is very little Alkalizate.  
Scurvygrass-seed makes a very small Bullition with Aq. fortis, like that of Ginger. So doth also the seed of Purslane.  
Hence, although there is much more of a certain kind of volatile Salt in Ginger or Scurvygrass, than in Purslane; yet there is as much of an Alkaly in any one, as the others.  
Colocynthis, Fruit-stones, the stony Covers of the seeds of Elder, white Bryony, Violets, and others, with Aq. fortis make a Bullition just perceivable without a Glass.  
Hence it appears, That the great Cathartick power of Colocynthis lieth not in an Alkaly, but an Acid; as making a much less Bullition, than some other vegetable Bodies, which are less Cathartick. For which reason likewise it is, That the best Correctors, or Refractors of the force of Colocynthis, are some kinds of Alkalies, as particularly that of Urine, as Riverius hath somewhere observed.  
The Root of Pyrethrum, with Aq. fortis, makes a Bullition and huff, in a short time.  
Hence, the Cause of a durable Heat, upon the Tongue, is an Alkalizate Sulphur. For the Heat of Ginger, though greater; yet abideth nothing near so long as that of Pellitory or Pyrethrum; which, as is said, maketh also a more sensible Bullition with Acids.  
Kermes-berries, commonly, but ignorantly, so called, with the said Liquor, huff up to an equal height, but in a somewhat longer time.  
Hence they are gently astringent; scil. as their Alkaly binds in with some preternatural Acid in the stomach.  
Hawthorn-stones, with Aq. fortis, huff up equally with the former Body; but the Bullition is not so visible. The like is also observable of Medlar-stones.  
Hence, as they contain a middle quantity of an Alkaly, they are not insignificantly used against the Stone.  
Seeds of Staphisagria, with Aqua fortis, make a Bullition still more visible. But it quickly ends.  
This confirms what was said before, sc. That the cause of a durable Heat is an Alkalizate Sulphur; these Seeds producing a durable Heat, as doth the Root of Pyrethrum.  
The seeds also of red Roses, Borage, and Comfrey do all with Aq. fortis make a considerable Bullition and huff; and that very quickly.  
So that amongst all Shells and Stones, those generally make the greatest Bullition, which are the hardest and the brittlest.  
Euphorbium makes a Bullition yet more considerable, with much froth, and very quickly.  
From which Experiment, compared with two of the former, it appears, That Euphorbium is not an acid, but an alkalizate Gum. As also, that the cause of its so very durable Heat, is an alkalizate Sulphur, as of Pyrethrum and Staphisagria hath been said.  
It seems also hence evident, that the power of all great Sternutatories lieth not in their Acid, but their Alkalies.  
The Arenulae or little stones in Pears, clustered round about the Coat, with Aq. fortis, presently huff up, and make a great Bullition and Effervescence, much greater than do any of the Body's abovenamed.  
Whence, although, so far as I know, they have never yet been used in Medicine; yet is it probable, that they are a more potent and effectual Nephritick, than any of the Bodies aforesaid, and some of them usually prescribed.  
It is hence also manifest, That, according to what I have elsewhere 
* First Book of the Anatomy of Plants.  said, for the sweetening of the Fruit and Seed, the tartareous and alkalizate parts of the Sap are precipitated into their stones, stony parts, and shells.  
The last Instance shall be in the shells of the seeds of Milium Solis; which not only with Aq. fortis, but some other Acids, make a greater and quicker Bullition and Effervescence, than any other vegetable Body, upon which I have yet made trial, in its natural estate.  
Hence, as well as from divers of the last foregoing Instances, we have a clear confirmation of what I have, towards the beginning of this Discourse, asserted; sc. That there is an alkalizate Salt existent in Plants, even in their natural estate. As also, that they are as significantly used against the Stone, quatenus alkalizate, as Millepedes, Eggshells, or any other testaceous Bodies of the same strength.  
To these I shall subjoin one or two Examples of Vegetable Bodies which are more or less altered from their natural estate.  
Neither Crystals of Tartar, nor Tartar itself (although they have some store of alkalizate mixed with their acid parts) make any Effervescence with Acids, but only with Alkalies, as Spirit of Heart's Horn, etc.  
Hence the calculous sediment of Urine, not so properly called the Tartareous part of the Urine; from the quite contrary events following its mixture with the aforesaid Salts; as will be seen hereafter.  
Spirit of Scurvygrass maketh no Luctation with any acid.  
Hence (as from a former Experiment was above-noted) it seems, That there may be a kind of volatile Salt, which is neither acid, nor alkalizate; such as this of Scurvygrass and other like Plants seems to be: scil. such a Salt as is not properly alkalizate, and yet contrary to an acid; as experience shows in its efficacy against the acid Scurvy.  
Rectified Spirit of Wine, both with Spirit of Nitre, and with Oil of Vitriol, severally, maketh a little Luctation.  
Which argues, that there is contained, even in this Spirit, some portion of a volatile Alkaly.  
Spirit of Wine, and double Aqua fortis, as the strongest is called, make an effervescence so vehement, as plainly to boil.  
Besides the vehemence hereof, there is another surprising circumstance. For whereas all other Liquors which make an Effervescence together, will do it in any quantity assigned to either of them, although but one drop to a thousand: on the contrary, these two, sc. rectified Spirit of Wine and Aqua fortis, require a certain proportion the one to the other. For if into no more than six drops of Spirit of Wine you put in but two or three of Aq. fortis, they stir no more than if you put in so much Water: but drop in about seven or eight drops of Aq. fortis, and they presently boil up with very great vehemency.  
Hence we may conceive the reason of the so very sudden access of an acute Disease, and of its Crisis. These not beginning gradually with the Cause; but then, when the Cause is arrived unto such an 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉, or such a certain Proportion, as is necessary to bring Nature to the contest. And these may serve for Examples upon Vegetables.   

CHAP. II.  
HAving given several Instances of trial upon Vegetables; I next proceed to Minerals, which, for some order's sake, I shall distribute into five or six sorts, sc. Earth's, Stones, Oars and Metals, Sulphurs, and Salts.  
First for Earth's. Oil of Vitr. upon Fuller's Earth, doth not stir it, or cause the least Bullition. Nor upon yellow Ochre. Nor upon the Ochre which falls from green Vitriol. The same Oil of Vitr. and Spir. of H. Horn poured severally upon Bolus Armena of two kinds, and upon one kind of Terra sigillata, stir none of them.  
Hence Bolus' are the Beds, or as it were, the Materia prima, both of opacous Stones and Metals; into which the said Bolus' are transmuted, by being concentred with divers kinds of Salts and Sulphurs, which successively flow in upon them.  
Aqua fortis, and Oil of Vitr. being poured severally upon another sealed Earth, which was vended by the name of Terra Lemnia; they both made a very considerable Effervescence herewith.  
Whence it appears, That there is no small difference in the nature, and therefore the operation of Bolus Armena and Terra Lemnia. As also, betwixt the sealed Earth's themselves, one making a great Effervescence, another none at all. Whereto, those that use them, are to have regard.  
Next for Stones. And first Spir. of Nitre upon Tripoli, stirreth it not in the least.  
Irish Slate, with Spirit of Hartshorn, maketh a small, yet visible Bullition: and it presently ceaseth. So that it seems to be nothing else but a Vitriolic Bole. As is also argued from its taste, which is plainly acid, and somewhat rough.  
Whence also it is with good reason given upon any inward Bruises. Because by coagulating the Blood, it prohibits its too copious afflux into the affected part. Yet being but gently astringent, and so the Coagulations it makes, not great; they are likewise well enough carried off from the same part in the Circulation; by both which means an Inflammation may be either prevented, or the better overruled.  
Lapis Haematites maketh no Effervescence at all either with Alkalies or A●●d●.  
〈◊〉 of the green part 〈…〉 Magnet with Oil of vitriol maketh some few bubbles, yet not visible without a Glass.  
But the podwer of the black part of a Magnet, which is the said stone fully perfect, stirreth not with any acid. Neither doth the calcined Magnet.  
Hence there is some considerable difference betwixt Iron and the Magnet.  
Lapis Lazuli, with Oil of Vitriol, and especially with Spirit of Nitre, maketh a conspicuous Bullition.  
Hence its Cathartick virtue lieth in an Alkaly. For which reason it is also appropriate, in like manner as Steel, to the cure of Hypochondriacal Affections; originated from some kind of fermenting Acid.  
Osteocolla, with Spirit of Nitre maketh yet a greater Effervescence.  
How it comes to be so great a knitter of broken bones, as it is reputed, is obscure. It seemeth, that upon its solution by a Nitrous acid in the body; it is precipitated upon the broken part, and so becomes a kind of Cement thereto.  
Lapis Tuthiae, with Spirit of Nitre, maketh an Effervescence much alike. And with Oil of Vitriol very considerably.  
But Lapis Calaminaris with Oil of Vitriol grows stark; as the powder of Alabaster doth with water. With spirit of Nitre it maketh a little Bullition, and quickly. But with Aq. fortis, a great one; beyond any of the stones abovenamed.  
Hence both Tutty and Calamy are Ophthalmicks from their Alkaly. Which is also confirmed, from the efficacy of some Alkalies of the like use.  
Hence also Calamy seemeth to partake somewhat of the nature of Silver: as by trial made upon that also, will hereafter better appear.  
Chalk and Oil of Sulphur or Vitriol make as strong an Effervescence as any of the rest.  
Whence it is sometimes well used against a Cardialgia.  
Whiteing makes as great an Effervescence as Chalk. So that it seems the saline parts are not washed away with the water, wherein the Chalk, for the making of Whiteing, is dissolved.  
Talk will not stir in the least either with spirit of Nitre, or Cil of Vitriol.  
But that which is called the Lead-Spar maketh a considerable Effervescence with both of them severally.  
Hence, however this be called English Talk, yet there is no small difference betwixt this and true Talk.  
To these stones may be added petrified bodies. As petrified wood; which (that upon which I made trial) no acid stirreth in the least.  
Petrified shells; upon four or five several sorts whereof Oil of Vitriol being poured, produceth a great Effervescence.  
The Root or rougher part of the Stone called Glossopetra, with spirit of Nitre, maketh a conspicuous Bullition.  
Asteria, the Stone so called, and found in some places in England, with Oil of Vitriol, maketh an Effervescence at the same degree. So doth the Belemnites, or Thunder-stone, both the larger and the lesser kinds.  
So that none of these are acid, or vitriolic, but alkalizate Stones.  
Coralline, with Oil of Vitriol, makes a conspicuous Bullition, yet mild and gentle; that is, with very little, if any heat, and without any visible Fumes. And red and white Coral do the like.  
Hence they are all of a very gentle operation, and fit for Children, as the case requires.  
Magistery of Coral (prepared the ordinary way) stirreth not in the least, either with Alkalies or Acids.  
Whence it is evident, That its active Principles are in its preparation destroyed and washed away: that is to say, It is an elaborate Medicine good for nothing. And thus far of Stones.  
I next come to Metals and Oars. And first for Lead; upon which spirit of Salt, spirit of Nitre, or Aq. fortis being dropped, it stirreth not in the least with any of them: but with Oil of Sulphur, and especially with Oil of Vitriol it maketh a slow Bullition and froth.  
Hence it seemeth to b● the most alkalizate Meta● Which is also confirme● by a foregoing Experiment upon the Lea●● Spar, which maketh considerable Effervescence with any sort o● acid. And which likewise being calcined, yieldeth a good quantity of Lixivial Salt.  
Lead-Ore stirreth not at all with Aq. fortis or Oil of Vitriol. But spirit of Salt makes it bubble, and spirit of Nitre makes it boil.  
Hence there is a considerable difference betwixt the perfect Metal and the Ore.  
Burnt Lead and red Lead, make a very small Bullition with Oil of Vitriol, with spirit of Nitre a far greater.  
Mercury, with Oil of Vitriol, will not stir, nor with Oil of Sulphur. But with spirit of Nitre presently boils up.  
Hence Mercury is a subacid Metal; spirit of Nitre being a subalkaliza● Acid.  
The filings of Iron o● Steel, with Oil of Vitriol make a fair Bullition, like that of Minium. But spirit of Nitre makes them boi● with much celerity.  
Hence Iron is likewise a subacid Metal.  
Steel prepared with Sulphur maketh a far less Effervescence with the same spirit of Nitre, than do the filings.  
Hence there is a great difference in their strength. So that ten grains of the filings unprepared, will go as far as fifteen grains or more of those which are prepared, as abovesaid. Yet ●n some cases the weaker and milder may be the better.  
There is one circumstance in the mixture of Steel and Aq. fortis, which is surprising; and that is this, That strong Aqua fortis, dropped upon Steel, will not, of itself, make th● least Bullition: but if here to you only add a drop o● two of Water, they presently boil up with very gre●● vehemency.  
The cause is obscure yet it is well known, tha● Water itself will dissolv● Iron: so that it appears as well by this, as by som● other Experiments, tha● even in Water, as mild a● it is, there is some kind o● corrosive Principle.  
Antimony with spirit o● Nitre, and Aq. fortis severally, maketh an Effervescence; somewhat lower than Iron. With Oil of Vitriol the Bullition is so small, as difficultly to be perceived with a Glass.  
Hence it seemeth to be of a very compounded nature; if I may so call it, a subacido-alkalizate Metal.  
Crocus Metallor. with spirit of Nitre, makes a very little Effervescence.  
Whence the Metalline Salt is not wholly lost in the preparation, but only diminished.  
Antimonium Diaphoreticum, with Spirit of Nitre and Oil of Vitriol severally, makes a considerable Effervescence.  
Wherefore it is not an useless Preparation; as from the Calcination and Ablution used therein, some have thought.  
Bezoardicum Minerale, (that upon which I made trial) stirreth not at all either with Alkalies or Acids.  
To which, let those who make use of it, have regard.  
Tin, with Spirit of Nitre, makes so hot and vehement an Effervescence, that it turns presently, as it were, into a Coal. It makes also a fair Bullition with Oil of Vitriol. And a gentle one with Spirit of Salt.  
Wherefore it hath something of the nature both of Iron, Led, and Copper.  
The like remarkable circumstance is seen in the mixture of Aq. fortis with Tin, as with Iron. For Tin and Aqua fortis of themselves will not stir; but add a few drops of Water to them, and they boil up with the greatest vehemency.  
Copper, with Spirit of Salt, and Oil of Vitriol severally, stirs not at all. Spirit of Nitre, and Aqua fortis, both boil it up vehemently.  
Neither Spirit of Hartshorn, nor Spirit of Salt Armoniac maketh any Bullition therewith. But both of them, by a gentle solution, that is, gently separating its Sulphur from its Salts, turn it blue.  
Hence Copper hath a greater proportion of acid than any of the forementioned Metals.  
Silver neither with Spirit of Salt, nor Oil of Vitriol makes any Bullition. With Spirit of Nitre it makes one, but 'tis soon over: and then continues to dissolve slowly into white Coagulations. It also maketh with Spirit of Hartshorn, or of Salt Armoniac, a full and deep blue.  
Hence there is a greater proportion of acid in Silver, than in Lead, Mercury, Iron, Antimony, Tin, or Copper.  
Litharge of Silver maketh the greatest Effervescence with Oil of Vitriol. Yet some with Spirit of Nitre. And with Spirit of Salt Armoniac maketh some little huff or elevation. And being mixed with Spirit of Nitre and Spirit of Salt Armoniac both together, produceth a faint blue.  
Hence, although the far greater part of this lethargy be but Lead; yet it seems it hath some small mixture of Silver. But that of Gold seemeth, for contrary reasons, not to have any Gold.  
Gold maketh no Effervescence with any single Salt I know of. But it is commonly dissolved with Aqua Regis, which is known to be a very alkalizate Liquor.  
Whence it seemeth●▪ That as Lead is the most alkalizate, so Gold the most acid of Metals.  
These things considered, and other observations added hereunto, may possibly give some directions, not only for the ordering and using, but even for the making, imitating and transmuting of Metals. Thus far of Metals.  
I will next give one or two Instances of trial upon Sulphurs. And first Sulphur vive, with Aq. fortis, maketh an apparent Bullition, but it is some time, before it begins. But the factitious or common Brimstone, maketh scarce any, if any at all.  
So that there is no small difference betwixt them.  
White and yellow Arsenic make no Bullition either with Alkalies or Acids.  
Wherefore the strength of its operation on the Body, lies more in a Sulphur, than a Salt.  
The ashes either of Pit-Coal, or Sea-Coal, make no Effervescence with Alkalies or Acids.  
Whence the saline Principle is altogether volatile, and sublimed away by the fire.  
Lastly for Salts. And first of all, Borax maketh no Effervescence nor any Fumes with Oil of Vitriol or Spirit of Nitre.  
Hence, it is of a very different nature from Salt Armoniac.  
Oil of Vitriol and Nitre make fumes or steams, though no Effervescence.  
Green Vitriol, with Spirit of Hartshorn, is scarcely moved. White Vitriol, with the same Spirit, maketh a conspicuous huff. And Roman Vitriol a vehement Effervescence.  
Whence the former is the least acid, and the latter the most of all. Which also confirms what I said before of the like natures of the several Metals to which they belong.  
Salt of Vitriol, though a fixed Salt, and made by Calcination, yet maketh no Effervescence with the strongest acid; but only with Alkalies; as may be seen upon their mixture, but much better heard by holding the mixture to ones ear.  
Hence, there are fixed Acids. Which further confirms what I have above asserted concerning the nature of Gold, scil. That the predominant Salt thereof is a fixed Acid.  
Sal Martis, with Spirit of Hartshorn, maketh a considerable huff.  
Hence it is much more acid than green Vitriol; and is therefore a cooler body.  
Alum and Sp. of Hartshorn make a plain Effervescence.  
Saccharum Saturni with Oil of Vitriol, stirs not at all. With Spirit of Salt, huffs a little. With Spirit of Nitre much more.  
Hence the acid of the Vinegar, and not the Alkaly of the Lead, is the predominant Principle.  
Common Salt stirs neither with Spirit of Salt, nor with Spirit of Nitre; nor with Aq. fortis▪ But with Oil of Vitriol it maketh a great Effervescence with noise and steams.  
Hence, even common Salt, though it be not reckoned amongst alkalizate Salts, yet is far nearer in nature to that, than to an acid. Hence also the Spirit of Salt is a subalkalizate Acid, and of a very different nature from Oil of Sulphur or Vitriol.  
Salt Armoniac, with spirit of Nitre, stirreth not. But with Oil of Vitriol it maketh a great Effervescence.  
Hence spirit of Nitre is a subalkalizate spirit.  
Oil of Vitriol and spirit of Nitre, though both acids, yet make a great smoke; greater than that which the spirit maketh of itself. Which confirms the last preceding Corollary.  
Oil of Vitriol and spirit of Salt, though both acids, yet make a strong Effervescence, with noise and fumes.  
Which further confirms, what was noted before, scil. that Spirit of Salt is a subalkalizate Acid.  
Spirit of Salt Armoniac with Oil of Vitriol, make an Effervescence so extraordinary quick, and as i● were instantaneous, tha● nothing seemeth quicker.  
Whence it is probable That if Gunpowder wer● made of Salt Armoniac instead of Nitre, or with both mixed together; it would be far stronger, than any kind now in use. And thus far for Minerals.  
I have only one Corollary to add, from the whole; which is, That whoever doth undertake the Natural History of a Country, (such as that the Learned Dr. Plot hath excellently performed of Oxford-shire) the foregoing Method, seemeth so easy, cheap, and indeceitful for the finding out and well distinguishing the natures of all kinds of Metals, Oars, Salts, Earth's, Stones, or other subterraneal bodies; as cannot, I think, be supplied but by others of greater difficulty and expense.   

CHAP. III.  
I Now proceed to the several Parts of Animals; as Hairs, Hoofs, Horns, Shells and shelly▪ Infects, Bones, Flesh and the several Viscera, Silk, Blood, Eggs, Musk, Castor, Gall, Urine, Dungs, Salts, and Stones.  
And first of all, the Hair of a man's head, with Oil of Vitriol, maketh no Bullition at all. Nor yet with spirit of Nitre.  
So that although it contains a good deal of volatile Salt; yet it seemeth either not to be alkalizate, or else is centred in so great a quantity of Oil, that the acid menstruum cannot reach it.  
Hare's Fur, with spiri● of Nitre, maketh, although a short, yet very plain Bullition and huff.  
Hence the Hair, an● therefore the Blood, o● some Animals, is fuller o● Salt, at least of an alkalizate Salt, than that o● some others. And perhaps the Hair of some men, a● of Blacks, may be so ful● of Salt, as to make a Bullition like Hare's Fur.  
The shave of Nai●● stir not at all, either wit● Oil of Vitriol, or spirit o● Nitre: only with the latter they turn yellow.  
Elks Claws, with spirit of Nitre, make a small and slow Bullition.  
Horse's Hoof, with Oil of Vitriol, stirs not of many hours. But with spirit of Nitre, allowing it some time, makes a very plain Bullition, and huffs up very high.  
Cow's Horn, neither with Oil of Vitriol, nor with spirit of Nitre, maketh any Bullition, only turneth to a yellow colour.  
Ram's Horn stirs no● with Oil of Vitriol; bu● with spirit of Nitre, make● a small and slow Bullition  
Hartshorn makes ● considerable Bullition a●● huff, even with Oil of Vitriol, which the rest of th● Bodies abovesaid, will n●● do. But with spirit of Nitre, it makes yet a greater.  
From the foregoing Experiments, and almost all that follow, what wa● formerly asserted of the Salts of Vegetables and Minerals, is here also evident concerning that of Animals, scil. That it is not made, but only separated by the fire.  
It likewise hence appears, That the proportion of Salt in the forementioned parts is very different; and that therefore some of them are never, and none of them but with good discretion, to be substituted one for another in Medicine.  
As also, that there is a different proportion of Salt in the several Animals themselves, to whic● the said Parts belong.  
Next for shells; as thos● of Lobsters, Eggs, Snail● and Oysters: all whic● make an Effervescence both with Oil of Vitriol and spirit of Nitre. Bu● with spirit of Nitre th● greatest.  
Lobster-shells make a considerable Bullition and huff but no noise, nor steams.  
Eggshells make a Bullition and huff, with some noise, but no steams.  
Snail-shells make an Effervescence with noise and steams.  
Oyster-shells make one with the greatest noise and thickest steams.  
Hence we may judge, in what case to administer one more appositely than another. As also in what proportion, according to their different strength. Some may be better for Children, as being milder. Or for a Body whose very sharp Blood or other Humours, are very easily kindled into Ferments. Or else may be safest, to avoid a sudden precipitation of the Humours; or for some other cause.  
Oyster-shells, and the rest abovesaid, make a quicker Effervescence, not only with spirit of Nitre, but even with spirit of Salt, tha● they do with Oil of Sulphur, or Oil of Vitriol.  
So that these Bodies, as well as Metals, have their proper Menstruums whereby they are best dissolved.  
Eggshells calcined, make with Oil of Sulphur, or Oil of Vitriol, or spirit of Nitre, a greater Effervescence, than when uncalcined. As also with steams; which uncalcined, they produce not.  
The like is seen in calcined Oyster-shells.  
The longer the Calcination is continued, the quicker and stronger will be the Effervescence. This I tried at several terms, from a quarter of an hour, to five hours. So that after so long a Calcination, they make an Effervescence almost instantaneous.  
The reason hereof is, Because the Sulphur, being for the greatest part driven away by the fire; the remaining Salt lies now more open and naked to the attaque of the Menstruum, so soon as ever they are mixed together.  
From hence it is plain, That Eggshells, and the others abovesaid, being burnt, are far stronger Medicines, than when unburnt.  
It is hereby likewise evident, That a great portion of their Salt, is not a volatile, but a fixed Alkaly.  
To these may be subjoined all kinds of shelly Infects. I will instance in three or four.  
And first Bees, with Oil of Vitriol, stir not in the least. With spirit of Nitre they make an exceeding small Bullition, without any elevation.  
Cochinele makes some Bullition with Oil of Vitriol, but very small: for the bubbles are not to be seen without a Glass. But with spirit of Nitre the Bullition is more visible, and joined with some elevation.  
Cantharideses make no visible Bullition with Oil of Vitriol. But with spirit of Nitre they do, and huff up rather more than Cochinele. Yet is this done very slowly, and comparatively with many other bodies, is not much.  
Hence it is not the quantity, but the quality of their volatile Salt, which makes them so strong an Epispastick. For most of those bodies above, and hereafter named, make a greater Bullition, and yet are neither Caustick nor Epispastick in the least.  
It is hence also evident, as hath been before suggested, That there are divers kinds of volatile Salts, eminently different; some being highly alkalizate, others very little, and some scarce any thing so: such as those of Scurvygrass, Anemone, Crowfoot, and many the like Plants; to whose Salts, this of Cantharideses seemeth to be very near of kin.  
Millepedes make a Bullition and huff, much greater and quicker, than any of the Infects abovenamed: and that both with spirit of Nitre, and Oil of Virtriol itself. Yet is this Insect of a very temperate nature.  
Whereby is further demonstrated, That the being simply alkalizate, is not enough to make a body to be Caustick.  
Again, although millipeds make a Bullition, greater than any of the Infects abovenamed: yet is it much less, than that of Oyster, Snail, or even Eggshells; and of divers other bodies above, and hereafter mentioned.  
Hence, being given to the same intent, as any of those bodies; it is the mildest and gentlest in its operation of them all.  
millipeds likewise calcined, make a stronger Effervescence, than when uncalcined, as do Oyster-shells, etc.  
So that it appears, That all Testaceous Salts, are, at least in part, fixed Salts.  
I next proceed to Bones. And first Whale-bone maketh no Bullition at all with any acid.  
A Cartilege, with spirit of Nitre, makes some very small bubbles, not to be seen without a Glass.  
The Bone in the Throat of a Carp, makes a little and slow Bullition with spirit of Nitre.  
The Spina of a Fish (that which I used was of a Codfish) maketh a Bullition one degree higher.  
All sorts of Teeth, as of Dogs, Boars, the Sea-Horse, Elephant, make the like. As also the Bone of an Ox's heart.  
So that all these are very gentle in their operation, and fit for Children.  
Sheep's and Calf's Bones both of them make a Bullition yet a little higher, especially with spirit of Nitre.  
Cock's Bones somewhat higher than the former.  
Cranium humanum a little higher than all the rest.  
Bones likewise, being calcined, make a Bullition with Acids. And so doth also calcined Hartshorn. But in neither of them, is the Bullition advanced by Calcination, any thing comparable to what it is in shells.  
Whence it appears, That the Salt of Horns and Bones, is much more volatile, than that of Shells.  
Next for Flesh and the several Viscera. And first, dried and powdered Mutton, with Oil of Vitriol, stirs not at all. But with spirit of Nitre makes a small Bullition and huff.  
Sheep's Heart doth the like somewhat more apparently.  
Viper's flesh produceth a froth, but huffs not.  
Powdered Earthworms make a great froth, and huff a little.  
Powdered Tripe makes only a little Bullition.  
Lamb-stones do the like.  
Kidney, Spleen, and Liver, with some elevation.  
Lungs, with bubbles very large; because extraordinary slowly.  
Dried Brain makes also a little and slow Bullition.  
Hence, there is a greater proportion of Sulphur or Oil, and less of an Alkaly in all these parts, than there is in Bones, Shells, and divers other parts hereafter mentioned. And in some of them, as in the Brain, that Salt which there is, may rather be lodged in some sanguineous parts mixed with them, than in their own proper substance.  
I proceed to instance in all sorts of Animal Contents.  
And first, raw Silk, with spirit of Nitre, makes a very small Bullition, but the elevation is considerable.  
The grumous part of the Blood dried, with Oil of Vitriol, stirs but little. But with spirit of Nitre it huffs up considerably.  
Serum of Blood dried, with the same spirit, makes a plain elevation, with a little Bullition.  
Herewith may be reckoned the White of an Egg, which is nothing but a pure Crystalline Serum separated from the common stock. This being dried, with spirit of Nitre, huffs up rather more than even the grumous part of the Blood, the bubbles are much larger, break oftener, and the elevation sooner made.  
Whence it seemeth, that there is a greater quantity of a volatile Alkaly in proportion to the Sulphur, requisite to the Generation, than to the Nutrition of an Animal.  
The Yolk of an Egg is scarce moved with spirit of Nitre, producing only a very few Bubbles. The Salt being either little alkalizate, or else immersed in so great a quantity of Oil, that the Menstruum cannot reach it.  
For the same reason Sperma Ceti stirs not with any Acid. Neither doth Civet.  
Russian Castor, with Oil of Vitriol, stirs not. But with spirit of Nitre makes a considerable huff and froth. Yet it requires time.  
Wherefore it seemeth, That Castor by virtue of its alkalizate Sulphur, becomes so good a Corrector of the acido-alkalizate Sulphur of Opium: so I take leave to call it, having some reasons to believe it such.  
Musk, with Oil of Vitriol, stirs not. But with spirit of Nitre it makes a considerable and quick Bullition, with large bubbles, which often break and rise again.  
Whence there is a very eminent difference betwixt Musk and Civet.  
Hence also, Musk is Cordial, not only from its Sulphur, but its Alkaly; by both directly opposite to preternatural Acidities.  
Dried Gall with spirit of Nitre for some time is still: but at length it makes a considerable Bullition and froth.  
The reason why it is so long before it begins, is because the Salt, (as was observed of some other Parts) is locked up in so great a quantity of Oil. The abundance whereof is manifest, not only from Distillation, but also from hence, In that the dried Powder, in lying by, incorporateth all together into one body, as Myrrh, and some other softer and oily Gums are used to do.  
Extract of Urine, with spirit of Nitre, makes a Bullition with some Effervescence, which continues for a considerable time; and at last it huffs up with great bubbles. The Bullition begins presently: the Salt being copious, and the Oil but little.  
The same Extract of Urine makes a considerable bullition and froth, not only with spirit of Nitre, but even with Oil of Vitriol.  
Hence the Salt of Urine is more alkalizate than that in most of the aforesaid Contents.  
From this and some of the following Experiments, it also appears, That the Salt which concurs to the generation or constitution of Gravel or of a Stone in the Kidneys or Bladder; is of a very different nature from the Salt of Urine.  
Next for Dungs. And first, dried Goats-dung makes, with spirit of Nitre, a small bullition, but no elevation. That of Mice the like. And that of Cows. So that of all I have tried, these three stir the least.  
Goose-dung, with spirit of Nitre, makes a very small bullition and some elevation. But it requires time. Oil of Vitriol stirs it not.  
Album Graecum, with spirit of Nitre, besides innumerable small bubbles, rises up with some great ones, exactly resembling the huffing up of Yeast or Barm. Also with Oil of Vitriol it maketh some little froth, but slowly.  
So that it should seem, that the Bones are a little opened by some acid Menstruum in the Dog's stomach (as the body of Steel is in its preparation with Sulphur) whereby it becomes a good mild Topick in Quinzies.  
Hen's dung, with spirit of Nitre, makes a very great bullition and huff: greater and quicker, than any of the rest abovenamed.  
But of all I have tried, Pigeons dung, with the same Spirit, maketh the greatest and the quickest Effervescence and huff; and that not without steams. Yet neither the same Dung, nor that of Hens, is moved in the least with Oil of Vitriol.  
The cause of so great an Effervescence in these, more than in the rest, is that white part which is here mixed in a great quantity with the Dung. Which white part, descendeth not from the Stomach, but is an Excrement separated from the Blood (as are Gall and the Succus Pancreaticus) by a peculiar Organ, which evacuates it into the Intestinum rectum; whence, together with the Stercus, it is excluded.  
Hence it is evident, That in the said white part of Hen's, and especially Pigeons dung, is contained a great quantity of a volatile Alkaly.  
I proceed to Salts. And first Salt of Blood and Urine both make a more durable Effervescence with Acids, than doth Salt of Wormwood, or Salt of Fern.  
Hence the former are more alkalizate, than the latter.  
Again, though divers other Animal Salts will not stir with Spirit of Salt, or with Oil of Sulphur or Vitriol; yet the Salt of Blood will make an Effervescence with all kinds of Acids.  
Whence it is further argued to be highly alkalizate, and very proper for the correction of all sorts of preternatural Acids in the body. There is little doubt, but that Spirit of Hartshorn will do the like.  
The Tartar or Gravel which precipitates out of Urine, with Oil of Vitriol, makes no bullition in the least. Nor with strong spirit of Salt. But with spirit of Nitre, it makes a very great one, with Effervescence and steams.  
From hence it appears, That there is much difference to be made in the use of acid Diuretics, Nephriticks, etc.  
And that I may not altogether omit to mention, what may be so much for the good of mankind, I do here declare, That for preventing the generation of the Stone, either in the Kidneys, or in the Bladder, there are not better Medicines in the world, than some certain Preparations of Nitre, duly administered. whoever shall think that any kind of acid, as Oil of Sulphur, Oil of Vitriol, Spirit of Salt, or the like, will have the same effects, will find themselves much deceived in their practice.  
I conclude with Stones. And first, Spirit of Nitre dropped upon a Stone of the Kidneys or Bladder produceth the very same effect, as upon the Gravel in Urine. That is to say, it makes it boil and huff up, until at length it is perfectly dissolved into a soft Pulp; which neither Oil of Sulphur, nor Oil of Vitriol, nor Spirit of Salt will do; nor give the least touch towards its dissolution.  
This confirms what I said before of the use of Nitre and Nitrous Spirits, if duly prepared and administered, above any other Acids, against the Store.  
Pearls, with any Acid, make the like Effervescence, as do Oyster-shells.  
Magistery of Pearls, as usually prepared, stirs not at all, with any Alkaly or Acid.  
So that as to the effect frequently intended by it, it is very insignificant; as of that of Corals hath been said.  
Crabs Eyes, with any Acid, make an Effervescence, almost as quick as that of Oyster-shells.  
Crabs Eyes likewise calcined, make a stronger Effervescence, than when uncalcined.  
So that these, as well as Shells, contain a fixed Alkaly.  
The stones in Whiting heads make a strong Effervescence like that of Oyster-shells.  
Stone of humane Gall, stirs not with Oil of Vitriol. But with spirit of Nitre maketh a little bullition just upon mixing, and after a considerable time, a little froth. Much less than what was observed before of the Gall itself.  
So that it seemeth to be generated of the Gall coagulated by some Acid, which hath already refracted the Alkaly wherewith the Gall abounds.  
This confirms the use of those Medicines in the Jaundice, or any other bordering Disease, which destroys those Acidities by which the Gall is curdled or coagulated, and so rendered more difficultly separable into the Guts.  
Bezoar, neither the Western, nor the Eastern, doth stir at all with Oil of Vitriol.  
Western Bezoar, with spirit of Nitre, makes a very little thin froth, and that's all; and that it doth very slowly.  
But Oriental Bezoar, with spirit of Nitre, after some time, maketh a very great Effervescence, with froth, elevation, noise, and steams▪ (as if you poured Oil of Vitriol upon Salt of Tartar) till it be wholly dissolved by the affused Spirit, and turned into almost a blood-red.  
Hence it may seem to be no mean Remedy against such fretting and venenate Acids, as oftentimes in Fevers, and other Distempers, lie about the Stomach, and are thence frequently translated to the Heart, Brain, Nerves, and other parts.  
The difference likewise betwixt the Western, and the Eastern Bezoar, is so great, that in any case of danger, and where the Bezoar is relied upon, it is an unpardonable fault, for the Apothecary, or any Person, to substitute the one for the other: unless he will take ten times as much, or ten times as little of the one, as he would have done of the other: if that will serve turn.  
The Stones already mentioned, are ordinarily generated in the bodies of Animals. I have one instance more of some other Stones which are extraordinary. In the City of Hereford lives a Maid, who often voids these stones, and in the space of some years last passed, hath voided several pounds, of several colours, and sizes, not only per vias urinarias, but also by vomit, and by stool. The first mention made to me of them, was by Mr Digges, a worthy Gentleman of that City, as a thing that was there much wondered at. And some of them, upon my desire, were sent me by Mr. Wellington, a noted Apothecary in the same place. I have tried what several acid Menstruums will work upon them; and find, That with Oil of Vitriol, and especially with spirit of Nitre the great ones make a very quick and conspicuous Effervescence. But the small ones, neither the white, nor the grey, make any bullition in the least: for in truth, they are no other but little Pibble and greet Stones.  
This being considered, and the various colours and mixture of any one of the great Stones, being well observed; it seemeth plain, That although she be somewhat old (above thirty years) yet may she have a kind of 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉, or diseased Appetite to Stones, Bones, Wood-ashes, Tabaco-pipes, Chalk, and such like things; which sometimes swallowing in little lumps, sometimes grossly, or finely ground betwixt her teeth; they are in her Stomach and Bowels, more or fewer of them, cemented together, either with a pituitous, bilious, or some other more or less glutinous substance. And that by virtue also of the said Cement, or any of the said, or other like alkalizate Bodies, the greater Stones, which consist of those partly, do make an Effervescence with acid Liquors. Thus far of Instances upon the parts of Animals. I shall close with some Corollaries deduced from the whole.  
And first, since we find, that amongst all the Menstruums we have made use of, Spirit of Nitre, or any very Nitrous Spirit, is the most universal dissolver of all kinds of Animal bodies; the best dissolver of many others both Vegetable and Mineral, and the only dissolver of some: Hence it is probable, That the great stomachick Menstruum, which either dissolves, or opens almost all Bodies which come into the Stomach, is a kind of Nitrous Spirit.  
Again, Spirit of Nitre being a subalkalizate Acid, and working more evidently upon Animal bodies, than other simpler Acids do, which yet are as strong; It hence follows, That most of the Salts of Animals are subacid Alkalies. How far this conclusion may further instruct us, I shall have occasion to show in another Discourse.  
Lastly, there being so many, say twenty or thirty degrees, from the slowest to the most vehement, in the Bullition of mixed Bodies; it seemeth, That Fermentation itself, as to the formal notion of it, is nothing else: or that from the common Luctation of mixed Bodies whereof we have now been speaking, it differs not in specie, but only in the manner of its causation, and in degree: the Aer, or some certain Menstruum lodged therein, being of no greater strength, than to produce a Bullition or Luctation of that low and soft degree, which we call Fermentation.  
I have thus endeavoured to prove, by various Instances, how instructive this most easy, plain and simple Method in the Mixture of bodies, may become to us: & that merely by observing the Luctations which thence arise betwixt them. How much more then, if a diligent remark be made of all those various Colours, Smells, Tastes, Consistencies, and other Mutations thereupon emergent?  
FINIS.   

At a Meeting of the Council of the R. Society. January 21. 167 4/ 5.  
Ordered,  
THAT a Discourse made before the R. Society, Decemb. 10. 1674. by Dr. Nehemiah Grew, Concerning the Nature, Causes, and Power of Mixture, etc. be Printed by the Printer of the R. Society.  
Brouncker. P. R. S.   

A DISCOURSE Made before the ROYAL SOCIETY, Decemb. 10. 1674. Concerning the Nature, Causes, and Power of MIXTURE. By Nehemiah Grew, M. D. and Fellow of the R. Society.  
LONDON, Printed for John Martin Printer to the Royal Society, and are to be Sold at the Bell in St. Paul's Churchyard, 1675.   

To the Right Honourable WILLIAM Lord Viscount BROUNCKER, PRECEDENT of the ROYAL SOCIETY.  
My Lord,  
ONE Reason why I dedicate the following Discourse to Your Lordship, is because by Your great and undeserved respects, You have obliged me to do no less. How much more I cannot say, unless I were able to compute the value of Your obligation.  
Another Reason, my Lord, is because I could not but publicly return Your Lordship thanks, for minding the Royal Society of so good a way, as they are lately resolved upon, for the management of a great part of their business. Wherein, my Lord, I do more than presume, that I also speak the sense of the whole Society; I think, not any one excepted.  
I may with the same confidence intimate, my Lord, how happy they account themselves, in having a Person so fit to preside their Affairs, as Your Lordship▪ The largeness of Your Knowledge, the exactness of Your Judgement, the evenness of Your Comport; being some of those necessary Qualifications, which His Majesty had in His eye, (as right well understanding what He did) when He fixed His choice upon Your Lordship.  
I know, my Lord, that there are some men, who have just so much understanding, as only to teach them how to be ambitious: the flattering of whom, is somewhat like the tickling of Children, till they fall a dancing. But I also know, that Your Lordship unconcerneth yourself as much, in what I even now spoke; as Caesar did himself, when his Soldiers began to style him King. For as he said, Non Rex, sed Caesar: so let Your Lordship be but once named, and all that follows, is but a Tautology to what You are already known to be. Your being Precedent of the Royal Society, Your being the first that was chosen, and chosen by so Wise a King; amounteth to so high and real a Panegyric to Your Lordship, as maketh verbal ones to be superfluous, and leaves them without any sound.  
Whence, my Lord, I have a third Reason most naturally emergent; which is, that I dare to submit myself, as to what I have hereafter said, to Your Lordship's Censure. You being so able, and just an Arbiter, betwixt the same and all those persons therein concerned; that You can neither be deceived, nor corrupted, to make a Judgement in any Point, to the injury of either.  
And truly, my Lord, were it only from a principle of self-interest, yet I could not desire it should be otherwise. For the World, if it lives, will certainly grow as much wiser than it is; as it is now wiser than it was heretofore. So that we have as little reason, to despise Antiquity; as we can have willingness, that we ourselves should be despised by Posterity.  
Yet some difference there is to be made; viz. betwixt those of all Ages, who have been modestly ignorant; and those who have thought, or pretended, that they were Omniscient. Or if knowing and acknowledging that they were ignorant; have yet not been contented to be so; unless, with as good manners, as sense, they did conjure all Mankind, not to offer at the knowing any more than themselves.  
Upon the whole, my Lord, I desire not You should be a Patron, any further than You are a Judge. For if this small Essay hath deserved the least acceptance, I am sure, that in being one, You will be both. Whereby, my Lord, You will not a little nourish and inspire my future endeavours of the like nature: being very solicitous to approve▪ myself,  
My Lord, Your Lordship's most faithful and obedient Servant, Nehemiah Grew.   

A DISCOURSE Made before the ROYAL SOCIETY.  
HAVING the honour to perform the task of this day; I shall endeavour to conform to the Philosophy, which this Society doth profess; which is, Ratiocination, grounded upon Experiment, and the Common Notions of Sense. The former being, without the latter, too subtle and intangible; the latter, without the former, too gross and unmanageable: but both together, bearing a true analogy to ourselves; who are neither Angels, nor mere Animals, but Men.  
The Subject I have chosen to speak of, is Mixture. Whereof, that our Discourse may be the more consistent, and the better intelligible; all I have to say, shall be ranged into this Method; viz.  
1. First, I shall give a brief account of the received Doctrine of Mixture.  
2. Next, lay down some Propositions of the Principles whereof all Mixed Bodies consist.  
3. Then, open the true Nature of Mixture; or say, What it is.  
4. And then enumerate the Causes of Mixture; or say, How it is made.  
5. Lastly, I shall show the Power of Mixture; or, What it can do.  

SECT. I.  
FIRST, As to the received Doctrine of Mixture; not to trouble you with tedious quotations of what Aristotle, Galen, Fernelius, Scaliger, Sennertus, Riverius, and others say hereof; we may suppose the whole summed up in that Definition which Aristotle himself hath given of it, and which the greater number of his Followers, have almost religiously adhered to; viz. that 'tis, 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉. Lib. 1. de Gener. & Corrupt. Cap. ult. that 'tis, Miscibilium alteratorum unio. Which Definition, as it is usually explicated, is both unintelligible, and Unuseful.  
Two things are unintelligible; what they mean by Alteration; and what by Union. In this Alteration, they say, That the very Forms of the Elements are altered. And therefore lay it down for an Axiom, Quòd in Mixto, Formae Elementares tantum sint in potentia. But let us see the consequence. For if in a mixed body, the Forms of the Elements are but in potentia; then the Elements themselves are but in potentia: for we all say, Forma dat esse. And if the Compounding Elements, are only in potentia; then the Compound; Body itself can be only in potentia: yet to say it is no more, is most absurd.  
As for the Union of Elements in a mixed Body; they make it such, as brings them at last to assert, the Penetration of bodies, and that the Union of mixed bodies is nothing else. For they say, it is made in such sort, that every particle of the mixed body, partaketh of the Nature of the whole. Which Nature, ariseth from the contemperated Qualities of the four Elements. Whence they conclude, That every particle of the mixed body, containeth in itself all the four Elements. Which is plainly to assert a penetration of bodies. For every Element is, at least, one particle; if therefore every particle of the mixed body, containeth four Elements; then four particles, are but one. I conclude then, That the received Doctrine of Mixture, is unintelligible.  
Whence it follows, That it is also Barren and Unuseful. For who can make any use of that which he understandeth not? And the experience of so many years, wherein it hath been ventilated by the disputes of men, proveth as much: Scarce any of them, except the Learned Sennertus, daring to venture upon Experiment, for fear they should come to understand themselves.  
It is confessed, that many gallant things have been found out by artificial Mixture. But no thanks to this Definition of it. For as an Ignorant Person may make bad Work, and a good Rule be never the worse; so an Ingenious Person may make good Work, and a bad Rule be never the better. The question is not, what have men done? but what have they done upon this foundation, Quòd Mixtio sit miscibilium alteratorum unio. Had this ever taught them to do any thing, even so much as to make the Ink wherewith they have wrote all their Disputes; I confess, they would have had something to show for it. But the truth is, their notions of Mixture, have been so far from doing us any good, that they have done us much harm: being, through their seeming subtlety, but real absurdity, as so many fantastic Spectrums, serving only to affright men from coming near them, or the Subject whereof they treat.  
I shall therefore endeavour to open the true Nature of Mixture. And I shall build my Doctrine upon the Common Notions of Sense: which none can deny; and every one may conceive of. In order to which, I shall take leave to lay down some Propositions, of the Principles of all mixed bodies.   

SECT. II.  
1. AND first, by Principles, I mean Atoms, or certain sorts of Atoms, or of the simplest of Bodies. For otherwise they would not be Principles; for a compounded Principle, in strict speaking, is a contradiction. Even as five, three, or two, are not the Principles of Number, but Unites.  
2. Whence, secondly, it follows, that they are also Indivisible. Not Mathematically; for the Atoms of every Principle have their dimensions. But Physically; and so, what is but one, cannot be made two.  
If it be asked, Whether a Stick cut with a knife, be not of one, made two? I say, that a Stick, is not one body, but many millions of bodies; that is, of Atoms; not any one whereof is divided within itself, but only they are separated each from other, where the Knife forceth its way. As in the drawing of a man's Finger through an heap of Corn; there is no division made in any one Grain, but only a separation of them one from another, all remaining still in themselves entire. I say therefore, that what is physically one, is also most firm, and indivisible; that is, impenetrable: for penetration is but the separation, not the division of Atoms.  
3. Hence, thirdly, they are also Immutable. For that which cannot be divided, cannot be changed. So that of the whole World of Atoms, not any one hath ever suffered, or can suffer the least mutation.  
Hereupon is grounded the Constancy of Causes and Effects. So that, in all Generations, it is not less certain, that the self same Principle is still propagated from the same; than, that Man is from Man. Wherefore, Compounded bodies are generated; but Principles are not, but only propagated; that is, in every Generation, they pass, in themselves unaltered, from one body, into another.  
4. If Principles, or Atoms are all Immutable; it again follows, That they are of divers kinds. For one and the same Principle, or kind of Atoms, will still make the same thing, and have the same effect: so that all Generations would then be the same. Wherefore, since they are Immutable, they must be divers.  
5. This diversity, for the same reason, is not small, but very numerous. For as the World, taken together, is Nature's Shop; so the Principles of Things, are her Tools, and her Materials. Wherefore, as it speaks the goodness of a Shop; so the perfection of the Universe, That it is furnished with many Tools wherewith, and many Materials whereupon to work. And consequently, that Philosophy beareth best it's own name; which doth not strain all to two or three Principles, like two or three Bells in a Steeple, making a pitiful Chime: but trieth to rise up to Natures own number, and so to ring all the changes in the world.  
6. Yet doth not this vast Diversity, take away the Regiment and Subordination, of Principles. There being a certain lesser number of them, which either by their greater quantity, or other ways, have Rule and Dominion, in their several Orders, over all the rest. For wherever the Subject is Multitude, Order is part of its Perfection. For Order is Proportion. And how can Nature be imagined to hold Proportion in all things else, and not here? Wherefore, as certainly, as Order and Government are in all the parts of the Rational; so certainly, of the Material World.  
Whence it is, That although the Species of Principles be very numerous; yet the Principles called Galenical, Chemical, or any others, which do any way fall under the notice of Sense, are notwithstanding reduceable to a smaller number: viz. according to the number of Predominant Principles in Nature; or, at least, in this part of the Universe which is near and round about us. To the Power and Empire whereof, all other Principles do submit. Which Submission, is not the quitting of their own Nature; but only their appearance under the external Face or Habit of the said Predominant Principles.  
7. As there can be no Order of Principles, without Diversity; so no Diversity, but what is originally made by these two ways; sc. by Size and Figure. By these they may be exceeding different: and all other Properties besides, whereby they differ, must be dependent upon these two.  
8. Nor therefore, can they be of any other Figures, than what are Regular. For Regularity, is a Similitude continued. Since therefore all kinds of Atoms are divers only by their Size and Figure; if the self same Size and Figure were not common to a certain number of Atoms, they could not be said to be of any one kind▪ and consequently, if there were no Similitude of Atoms, there could be no Distinction of Principles.  
9 Hence also, these two Modes of Atoms, viz. their Size and Figure, are the true, and only original Qualities of Atoms. That is, an Atom is such or such, because it is of such a certain Size and Figure.  
10. Lastly, As these two Modes, taken severally, are the Qualities of an Atom: so considered together, they are its Form. A substantial Form of a Body, being an unintelligible thing. I say of a Body; for although the Rational Soul be a substantial Form, yet is it the Form of a Man, and not of a Body. For the Form of a Body, we can conceive of no otherwise, then as of the Modification of a Body, or a Complexion of all the Modes of a Body. Which also agrees with that Definition of a Form, which amongst the Peripatetic Philosophers is well enough accepted, viz. Quod sit, Ratio ejus Essentiae, quae cuique Rei competit. Which Ratio, if it be referred to a Body, what is it but the Modification of that Body? Having thus proposed a Summary of my Thoughts about Principles; I shall next proceed to show what their Mixture is.   

SECT. III.  
AND first of all, from the Premises, we arrive at this Conclusion; sc. That the Formation and Transformation of all Bodies, can be nothing else, but the Mixture of Bodies. For all Principles are immutable; as we have above proved: and therefore not generable, formable, or transformable. And the Forms of Principles, being but their Modes, are also immutable. So that the whole Business of the Material World, is nothing else, but Mixture.  
Again, as Nature worketh every where only by Mixture; so is this Mixture every where but one thing, and can be but one. For whether it be the Mixture of great Bodies, or of small; of Compounds, or of Atoms; it is every where Mixture, and the Mixture of Bodies. Wherefore, Mixture is either an intelligible Affection of all Bodies, or of none; which latter, no man will say. As many ways, therefore, as we can see, or conceive the Mixture of any gross Bodies, which we hold in our hand; so many ways, we may, of the subtlest Mixtures which Nature maketh, or of Atoms themselves; and no other ways.  
Now all the ways we can distinguish Mixture by, are in general these two; either in respect of the Bodies Mixed, or else of the Modes of the Mixture itself.  
In respect of the Bodies Mixed, Mixture is distinguished also two ways; viz. by Conjugation, and by Proportion.  
By Conjugation, I mean, a Certain Mixture of some such Principles, and not of others. Which is threefold.  
First, As to Number: as when one Body may be compounded of two Principles, another of three, a third of four, a fourth of five, and so on.  
Secondly, As to Kind: where, though there be a conjunction of the same Number, yet not of the same Kind.  
Thirdly, When they differ from one another both in Number and Kind.  
So many ways the Principles of Bodies may be conceived to be Conjugated; and therefore are: for here, that which may be, is. The Consequence is clear. For first, Nature hath various Materials wherewith to make these Mixtures; as we have showed. Secondly, By these Mixtures she may, and without the concurrence of any imaginary Forms, must produce all the varieties in the material world; as likewise hath been said. Wherefore, since all imaginable Mixtures may be made, and that to some purpose; if they should not be so, Nature would be Imperfect: because we ourselves can think, how she might put her Materials to further use, than so she would do.  
To think, therefore, that all kinds of Principles, or all Elements go to make up every Compounded Body; is a conceit, no more to be credited, than one that should tell us, all kind of Wheels and other parts of a Watch, were put into a Clock; or that there were no other Materials wherewith to build an House, then for a Tent or a Ship. For why should Nature, the great Artificer by which all perfect Works are made, be feigned to cram and ram all things into one, which we ourselves look upon as absurd?  
Secondly, The Mixture of Principles is diversified, as by Conjugation, so also by Proportion. That is, by the divers Quantities, of the several Principles or Parts mixed together.  
As if the quantity of one, were as five to ten; of a second, as five to fifteen; of a third, as five to twenty, etc.  
Or if that of one, be as five to six; of a second, as six to seven; of a third, as seven to eight. By which, and by other Proportions, Mixture may be varied innumerable ways.  
Again, As Mixture is varied with respect to the Bodies Mixed; so likewise in respect of the Mixture itself, which I call the Location of Principles, or the Modes of their Conjunction. Which may be various, as well as their Conjugation and Proportion. Yet are they all reduceable unto two general Modes: all Bodies, and therefore all Principles, being Mixed, either by Mediation, or by Contact.  
Now all Contact, whether of Compounds, or of Atoms, can be no other way, than such as is answerable to their Figures. Whereof, therefore, we can conceive but three general ways, viz.  
First, By Contact in a Point, or some smaller part: as when two Atoms meet, which are globular or otherwise gibbose.  
Secondly, By Contact in a Plain: as in the conjunction of the sides of Triangular or Quadrangular Atoms, or otherwise flat.  
Thirdly, By Contact in a Concave: as when one Atom is admitted into the Concave or hole of another; as a Spigot is into a Faucet.  
The first may be called, Apposition; the second, Application; the third, Reception or Intrusion.  
In the two last ways, Atoms may be joined by Mediation; but best of all the last. As when the two extremes of one Atom are received into the Concaves or the holes of two others.  
And these are all the general ways, whereby we can conceive Bodies to be Mixed together; sc. by their various Conjugation, Proportion, and Location.  
So that the Composition of Atoms, in Bodies; is like that of Letters, in Words. What a Thunderclap would such a Word be, as wherein all the four and twenty Letters were packed up? One therefore is compounded of more, another of fewer; this of some, and that of others: and both the Conjugation, Proportion, and Location of Letters is varied in every Word: whereby, we have many thousands of differing Words, without any alteration at all, in the Letters themselves; and might have ten times as many more. In like manner, therefore, or in the self same analogous' way, as the Letters of the Alphabet, are the Principles of Words; so Principles, are the Alphabet of Things.  
What we have said of Principles; and of Mixture as consequent thereupon; may be a foundation for an intelligible account, of the Nature and Cause of most of the Intrinsic Properties, and Qualities of Bodies: as of Gravity, Levity, Fixity, Fluidity, Angularity, Roundness, Heat, Cold, Blackness, Whiteness, Sourness, Sweetness, Fragrancy, Fetidness, and very many more. I say an intelligible account; sc. such as is grounded upon the Notions of Sense, and made out Mechanically. But the exemplification hereof, being too large a field for this, or any one Lecture, I shall, before I come to the Causes of Mixture, only deduce from the Premises, these following Corollaries.  
1. First, That there is no alteration of Principles or of Elements, in the most perfect Mixture of Bodies. It cannot be; for Principles are Immutable, as we have said. And if it could be, yet it needeth not to be: for they are also many, and compoundable infinite ways; as hath been showed. So that we have no need to perplex ourselves with any of those difficulties, that arise from the Doctrine of the Alteration of Elements. The ground of which conceit, is that, of there being but four Elements, and that all the Elements must needs be in every Body. And so men being puzzled, how from thence to make out the infinite variety of Bodies, they feigned them to be alterable, and altered, upon every perfect Mixture. Not considering, that if their four Elements be alterable; as few as they are, no fewer than three of them may be spared: for one Element, if alterable, may be made any.  
2. Hence, secondly, may be solved that great Dispute, Whether such as we call Lixivial Salts, are made by the fire?  
For first, No Principle is made by the fire: all Principles being unalterable; and therefore unmakeable.  
Secondly, We must therefore distinguish betwixt the Principle, and the Modification of a Principle; or its various Mixture with other Principles, whence it may receive a various denomination.  
Wherefore, a Lixivial Salt, qua Lixivial, is certainly made by the fire. But quatenus Salt, it is not: that Principle being extractable out of most Bodies; and by divers other ways, then by the fire. For whether you Calcine a body, or Ferment it, (after the manner showed by the diligent and curious Improver of Chemical Knowledge, Dr. Daniel Cox) or else putrify it under ground, or drown it in the Sea; it still yieldeth some kind of Salt. All which Salts are made, not by making the Saline Principle; but only by its being variously Mixed, upon those various ways of the Solution of Bodies, with other Principles: from which its various Mixture, it receives the various Denominations, of Marine, Nitrous, Volatile, or Lixivial.  
3. Hence, thirdly, the most perfect Mixture of Bodies, can go no higher than Contact. For all Principles are unalterable; and all Matter is impenetrable; as hath been said. In the most visible and lax Mixture, there is Contact; and in the most subtle and perfect, as in Generation itself, there is nothing more.  
4. Hence, fourthly, we easily understand, how divers of the same Principles, belonging both to Vegetables and many other Bodies, are also actually existent in the Body of Man. Because even in Generation, or Transmutation, the Principles which are translated from one body to another, as from a Vegetable to an Animal, are not in the least altered in themselves; but only their Mixture, that is, their Conjugation, Proportion, and Location, is varied.  
5. Hence also the difference of Mixture, arising from the difference of Contact, is intelligible; sc. as to those three degrees, Congregation, Union, and Concentration.  
Congregation, and Inconsistent Mixture, is when the several Atoms touch but in a Point, or smaller part▪ In which manner, I have divers arguments, inducing me to believe the Atoms of all Fluid Bodies, qua Fluid, do touch; and in no other.  
Union, is when they touch in a Plain. As in the Crystals and Shootings of all Salts, and other like Bodies. For if we pursue their divided, and subdivided parts, with our eye, as far as we can; they still terminate, on every side, in Plains. Wherefore, 'tis intelligible, That their very Atoms do also terminate, and therefore touch, in Plain.  
Concentration, is when two, or more Atoms touch by Reception and Intrusion of one into another: which is the closest, and firmest Mixture of all; as in any fixed, unodorable, or untastable body: the Atoms of such bodies, being not able to make any Smell or Taste, unless they were first dissolved; that is to say, unpinned one from another.  
6. Hence, sixthly, we understand, how in some cases, there seemeth to be a Penetration of Bodies; and in what sense it may be admitted: viz. if we will mean no more by Penetration, but Intrusion. For the Intrusion of one Atom into the Concave or hole of another, is a kind of Penetration; whereby they take up less room in the mixed Body, than they would do by any other way of Contact. As a naked knife and its sheath, take up almost double room, to what they do, when the knife is sheathed.  
Whence we may assign the reason, Why many Liquors being mixed; take up less room or space, than they did apart; as they very Ingenious M. Hook maketh it to appear by Experiment that they do. I say the plain reason hereof, or at least one reason, is the Intrusion of many of their Atoms one into another. Which yet is not a Penetration of Bodies strictly so called.  
7. If all that Nature maketh, be but Mixture; and all this Mixture be but Contact: 'tis then evident, That Natural and Artificial Mixture, are the same. And all those seeming subtleties whereby Philosophers have gone about to distinguish them; have been but so many Scarecrows, to affright Men from the Imitation of Nature.  
8. Lastly, Hence it follows, That Art itself may go far in doing what Nature doth. And who can say, how far? For we have nothing to Make; but only to Mix those Materials, which are already made to our hands. Even Nature herself, as hath been said, Maketh nothing new; but only Mixeth all things. So far, therefore, as we can govern Mixture, we may do what Nature doth.  
Which, that we may still the better understand; let us before, and in the next place, see the Causes of Mixture. For since Natural and Artificial Mixture are the same; the immediate Causes of both, are and must be the same.   

SECT. IV.  
NOW all the Causes of Mixture we can conceive of, must, I think, be reduced to these six in general; viz Congruity, Weight, Compression, Solution, Digestion, and Agitation.  
1. Congruity, or aptitude and respondence betwixt the Sizes and Figures of parts to be mixed: whereby bodies may be truly called the Instrumental Causes of their own Mixture. As when a plain answers to a plain, a square to a square, a convex to a concave, or a less to a greater or an equal, etc. according to which Respondencies in the parts of Bodies, they are more or less easily mingleable.  
2. Weight; by means whereof, all Fluid Bodies, upon supposition of the Congruity of their parts, must unavoidably mingle  
3. Compression; which either by the Air, or any other body, added to Weight, must, in some degree, further Mixture. Because, that Weight itself is but Pression.  
For further proof of all the said Causes, I made this Experiment▪ Let Oil of Aniseeds, and Oil of Vitriol be put apart into the Receiver of an Air-Pump. And, having exhausted it of the Air, let the two said Oils be then affused one upon the other. Whereupon  
First, It is visible, that they here mix and coagulate together; that is, their parts are wedged and intruded one into another, without the usual compression of the Air; for that is exhausted: and therefore only, by the Congruity of their receiving and intruding parts; and by their Weight; by which alone they are so compressed, as to make that Intrusion.  
Secondly, It is also evident, That although they do Coagulate; yet not altogether so much, as when poured together in the same manner, and quantity, in the open Air. Wherefore, Compression, whether made by the Air, or any thing else, doth somewhat further the Mixture of Bodies, and the greater the Compression, the more.  
4. Solution; For all bodies mix best, in Forma fluida. And that for two reasons.  
First, Because the parts of a body are not then in a state of Union, but of Separation; and therefore, in a more capable state, for their Mixture and Union with the parts of another body.  
Secondly, Because than they are also in a state of Motion, more or less; and therefore, in a continual tendency towards Mixture; all Mixture being made by Motion.  
Wherefore, all Generations, and most perfect Mixtures in Nature, are made by Fluids'; whether Animal, Vegetable, or Mineral. Which is also agreeable to the Doctrine of the Honourable Mr. boil, in his excellent Treatise of the Nature and Virtues of Gems.  
And 'tis well known, That bodies are ordinarily petrified, or Stones made, out of Water. That is, out of petrifying parts dissolved per minima in Water, as both their Menstruum and their Vehicle. Wherefore, if we will talk of making Gold; It must not be by the Philosopher's Stone, but by the Philosopher's Liquor.  
5. Digestion. For which there is the same reason, as for Mixture, by Solution. For  
First, All heat doth attenuate, that is, still further separate the parts of a body; and so render them more mingleable with the parts of another. And therefore  
Secondly, Doth also add more Motion to them, in order to their Mixture.  
6. Agitation. Which I am induced to believe a great and effectual means of Mixture, upon divers considerations. As  
First, That the making of Blood in the Bodies of Animals, and the mixing of the Chyle therewith, is very much promoted by the same means; sc. by the Agitation of the parts of the Blood and Chyle, in their continual Circulation.  
Again, From the making of Butter out of Milk, by the same means; whereby alone is made a separation of the oleous parts from the whey, and a mixture of them together.  
Moreover, From the great Effects of Digestion; well known to all that are conversant in Chemical Preparations. Which Digestion itself, is but a kind of insensible Agitation of the parts of digested bodies.  
'Tis also a known Experiment, That the readiest way to dissolve Sugar in Wine or other Liquor; is to give the Vessel a hasty turn, together with a smart knock, against any hard and steady body: whereby all the parts of the Sugar and Liquor, are put into a vehement Agitation, and so immediately mixed together.  
And I remember, that having (with intent to make Mr. Mathews' Pill) put some Oil of Turpentine and Salt of Tartar together in a bottle, and sent it up hither out of the Country; I found, that the continual Agitation upon the Road, for three or four days, had done more towards their Mixture; then a far greater time of Digestion alone had done before. And it is certain, That a vehement Agitation, especially if continued, or joined with Digestion; will accelerate the Mixture of some bodies, ten times more, than any bare Digestion alone; as may be proved by many Experiments.  
I will instance in this one. Let some Oil of Turpentine and good Spirit of Nitre be stopped up together in a bottle, and the bottle held to the fire, till the Liquors be a little heated, and begin to bubble. Then having removed it, and the Bubbles by degrees increasing more and more; the two Liquors will of themselves, at last fall into so impetuous an Ebullition, as to make a kind of explosion; sending forth a smoke for the space of almost two yards high. Whereupon, the parts of both the Liquors, being violently agitated, they are, in a great portion, incorporated into a thick Balsam in a moment: and that without any intense heat, as may be felt by the bottle. And thus much for the Causes of Mixture.   

SECT. V.  
HAVING enumerated the general Causes, we shall, lastly, inquire into the Power and Use of Mixture; or, into what it can Do and Teach. And I shall Instance in fix particulars.  
First, To Render all Bodies Sociable, whatsoever they be.  
Secondly, To Make Artificial Bodies in Imitation of those of Nature's own production.  
Thirdly, To Make or Imitate the sensible Qualities of Body's; as Smells, and Tastes▪  
Fourthly, To Make or Imitate their Faculties.  
Fifthly, It is a Key, to discover the Nature of Bodies.  
Sixthly, To discover their Use, and the Manner of their Medicinal Operation.  

Instance I.  
FIRST, To render all Bodies Sociable or Mingleable: as Water with Oil, Salt with Spirit, and the like. For Natural and Artificial Mixture, are the same; as we have before proved. If therefore Nature can do it, as we see in the Generation of bodies she doth; 'tis likewise in the Power of Art to do it.  
And for the doing of it, two general Rules result from the Premises, sc. The Application of Causes, and the Choice of Materials. As for the Causes, they are such as I have now instanced in. And for the Application of them, I shall give these two Rules.  
First, That we tread in Nature's steps as near as we can; not only in the application of such a Cause, as may be most proper for such a Mixture; but also in allowing it sufficient time for its effect. For so we see Nature herself, for her more perfect Mixtures, usually doth. She maketh not a Flower, or an Apple, a Horse, or a Man, as it were in a moment; but all things by degrees; and for her more perfect and elaborate Mixtures, for the most part, she requireth more time. Because all such Mixtures are made and carried on per minima; and therefore require a greater time for the completing of them.  
A second Rule is, Not only to make a due Application of the Causes; but sometimes to Accumulate them. By which means, we may not only Imitate Nature, but in some cases go beyond her. For as by adding a Graft or Bud to the Stock, we may produce Fruit sooner, and sometimes better, than Nature by the Stock alone would do: So here, by accumulating the Causes of Mixture; that is, by joining three, or four, or more together; or by applying more in some cases, where Nature applieth fewer; we may be able to make, if not a more perfect, yet a far more speedy Mixture, than Nature doth. As by joining Compression, Heat, and violent Agitation, and so continuing them all together, by some means contrived for the purpose, for the space of a week, or month, or longer, without cessation. Which may probably produce, not only strange, but useful effects, in the Solution of some, and the Mixture of other Bodies. And may serve to mix such Bodies, as through the small number of their congruous parts, are hardly mingleable any other way. Agitation being, as carrying the key to and fro, till it hit the lock; or within the lock, till it hit the wards.  
Secondly, For the Choice of Materials, if they are not immediately, that is, of themselves, mingleable; we are then to turn one species of Mixture into a Rule; which is, To mix them by mediation of some third, whether more simple or compounded body, which may be congruous in part to them both: as sulphurous Salts are to Water and Oil; and are for that reason mingleable with either of them.  
Or, By any two congruous Bodies, which are also, in part, congruous to two others: and other like ways. Whereby the parts of Bodies, though never so heterogeneous, may yet be all bound and locked up together. Even as twenty keys may be united, only by uniting the two Rings whereon they hang.  
The consideration of these things, have put me upon making several Experiments, for the Mingling of heterogeneous Bodies. I shall give two Examples of trial; the one upon fluid, the other upon consistent, Bodies.  
For the first, I took Oil of Aniseeds, and pouring it upon another Body; I so ordered it, that it was thereby turned into a perfect milk-white Balsam, or Butter. By which means the said Oil became mingleable with any other Liquor, Oil, Wine, or Water; easily, and instantaneously dissolving therein, in the form of a Milk▪ And note, That this is done, without the least alteration of the smell, taste, nature or operation of the said Oil.  
By somewhat the like means, not only Oil of Aniseeds, but any other stillatitious Oil, may be transformed into a perfect milk white Butter; and in like manner be mingled with Water or any other Liquor. Which is of various use in Medicine; and what I find oftentimes very convenient and advantageous to be done.  
Again, Not only fluid but consistent bodies, which of themselves will mix only with Oil; by due mixture with other bodies, may be rendered easily dissoluble in Water; as may Rosin, and all resinous and friable Gums. As also Wax: and this without changing much of their Colour, Taste or Smell. Whereof likewise, whatsoever others may do, the Physician may make a manifold Use.   

Instance II.  
BY Mixture also, we may be taught to Imitate the Productions of Nature. As to which, from what we have before said of Mixture, we may conclude; That there is no generation of Bodies unorganical, but what is in the power of Mixture to imitate. As of Animals, to Imitate Blood, Fat, Chyle, spital, Phlegm, Bile, etc. Of Vegetables, to Imitate a Milk, Mucilage, Rosin, Gum, or Salt. Of Minerals, to Imitate Vitriol, Allom, and other Salts; as also Metals, and the like.  
I do not say, I can do all this: but if upon good premises we may conclude this may be done; it is one step to the doing of it. But I will also give an Instance of somewhat that may be done in every kind. And  
1. First, For the Imitation of an animal body, I will instance in Fat. Which may be made thus; Take Oil Olive, and power it upon high Spirit of Nitre. Then digest them for some days. By degrees, the Oil becomes of the colour of Marrow; and at last, is congealed, or hardened into a white Fat or Butter, which dissolveth only by the fire, as that of Animals.  
In converting Oil thus into Fat, it is to be noted, That it hardens most upon the exhalation of some of the more Sulphureous parts of the Spirit of Nitre. Which I effected, well enough for my purpose, by unstopping the glass after some time of digestion; and so suffering the Oil to dissolve and thicken divers times by successive heat and cold.  
Hence, The true Congealing Principle, is a Spirit of Nitre separated from its Sulphur. For the better doing whereof, the Air is a most commodious Menstruum to the said Spirit of Nitre.  
Whence also, if we could procure such a Spirit of Nitre, we might congeal Water in the midst of Summer. We might also refrigerate Rooms herewith artificially. And might Imitate all frosty Meteors. For the making of Fat, is but the Durable Congelation of Oil▪ which may be done without frost, as I have showed how.  
Hence also it appears, That Animal Fat itself, is but the Curdling of the Oily parts of the Blood; either by some of its own Saline parts; or by the Nitrous parts of the Air mingled therewith.  
Hence likewise it is, That some Animals, as Coneys, and Fieldfares, grow fatter in frosty weather: the oily parts of the blood, being then more than ordinarily coagulated with a greater abundance of nitrous parts received from the Air into their bodies.  
For the same reason it is, That the Fat of Land-Animals is hard; whereas that of Fish is very soft, and in a great part runs to Oil, sc. Because the Water, wherein they live, and which they have instead of breath, hath but very few nitrous parts in it, in comparison of what the Air hath.  
2. For the Imitation of a Vegetable Body, I will give three Instances; In Rosin, Gum, and a Lixivial Salt. The first may be made thus; Take good Oil of Vitriol, and drop it upon Oil of Aniseeds; and they will forthwith incorporate together; and by degrees, will harden into a perfect Rosin; with the general and defining Properties of a truly Natural Resinous Gum. Being not in the least dissoluble in Water; or at least, not any more, than any natural Rosin or Gum: yet very easily by fire: as also highly inflammable: and exceeding friable.  
Although this artificial rosin, be the result of two Liquors, both which very strongly affect the Sense: yet being well washed from the unincorporated parts, (which is to be done with some care) it hath scarce any Taste or Smell.  
The Concentration of these two Liquors, is likewise so universal; that the Rosin is not made by Precipitation, but almost a total Combination of the said Liquors; and that with scarce so much, as any visible fumes.  
Again, Having taken a certain Powder and a Saline Liquor, and mixed them together in a bottle, and so digested them for some time; the Powder was at last transmuted to a perfect Oily Gum; which will also dissolve either in Oil, or in Water; in the self same manner, as Galbanum, Ammoniac, and the like will do.  
And Lastly, A Lixivial Salt may be imitated thus; Take Nitre, Oil of Vitriol, and high Spirit of Wine, of each a like quantity. Of these three Bodies, not any two being put together; that is to say, neither the Nitre with the Oil, nor the Oil with the Spirit, nor the Nitre with the Spirit; will make the least ebullition: yet all three mingled together, make a very conspicuous one. The Spirit of Wine being as the Sulphur; and so that, and the Nitre together, standing, as it were, in the stead of an Alkalizate, that is, a Sulphurous Salt, against the Oil of Vitriol. Divers other Experiments I can show of the like nature.  
3. In the last place, for the Imitation of a Mineral Body, I will instance in two, sc. Nitre and Marine Salt; if I may have leave to reckon them amongst Mineral Bodies. As for Nitre, by mixing of four Liquors together, and then setting them to shoot; I have obtained Crystals of true and perfect Salt; which have had much of a nitrous taste; and would be melted with a gentle heat, as Nitre is; and even as easily as Butter itself: I mean, not by the addition of any sort of Liquor, or any other body, to dissolve it; but only by the fire.  
And as for a Sea-Salt, that I might Imitate Nature for the making hereof, I considered, That the Salt so called, was nothing else but Animal and Vegetable Salt, freed from its true Spirit and Sulphur, and some Saline particles, specifically Animal or Vegetable, together with them. For both Animal and Vegetable bodies being continually carried by all Rivers into the Sea; and many likewise by Shipwreck, and divers other ways, immersed therein: they are at last corrupted, that is, their Compounding parts are opened and resolved. Yet the Resolution being in the Water, is not made precipitately, as it is in the Air; but by degrees, and very gently. Whence the Sulphurous, and other more Volatile parts, in their avolation, make not so much haste, as to carry the more fixed Saline parts along with them; but leaveth them behind in the Water, which imbibeth them, as their proper Menstruum.  
And the Imitation of Nature herein, may be performed thus; Put as much of a Lixivial Salt as you please, into a wide mouthed bottle, and with fair Water make a strong Solution of it; so as some part thereof may remain unresolved at the bottom of the bottle. Let the bottle stand thus for the space of about half or three quarters of a year, all the time unstopped. In which time, many of the Sulphurous and other more Volatile parts gradually flying away; the top of the unresolved Salt will be incrustate, or as it were frosted over, with many small and hard Concretions, which for their nature, are become a true Sea-Salt. Whereof there is a double proof; First, In that most of the said Concretions are of a Cubical, or very like Figure. Especially on their upper parts; because having a fixed body for their basis, their under parts, therefore, contiguous thereto, are less regular. Whereas the parts of Salt in the Sea, being environed on all sides with a fluid; their Figure is therefore on all sides regular. Secondly, In that a strong Acid Spirit or Oil being poured upon a full bodied Solution hereof; yet it maketh herewith no Ebullition; which is also the property of Sea-Salt. And thus much for the more general Imitation of Bodies.   

Instance III.  
FROM the aforesaid Premises, and by the aforesaid Means, there is no doubt to be made, but that also the other sensible Qualities of Bodies may be Imitated, as their Odours and Tastes. And that not only the general ones, as Fragrant, or Astringent: but also those which are specifical and proper to such a species of Bodies. Thus, for example, by mixing several Bodies together, in a due proportion, I have Imitated the Smells of divers Vegetables; as of Tansy, of Lignum Rhodium, and others. And I conclude it feasable, To Imitate the Taste or Smell of Musk, or Ambergris, or any other body in the world.   

Instance IU.  
HENCE also we may be Taught, How to Imitate the Faculties, as well as other Qualities of Bodies. The reason is, because even these have no dependence upon any substantial Form; as in the first Part of my last Book of the Anatomy of Vegetables, I think, I have, in a few lines, clearly made out: but are the mere result of Mixture; effected by the same Causes, whether in Nature or Art; as also in the premises of this Discourse hath been showed.   

Instance V.  
FROM whence, again, it is likewise a Key to Discover the Nature of Bodies. For how far soever we can attain to Mingle, or to Make them, we may also know what they are.  
For Bodies are mingleable, either of themselves, or by some third. As to those which mingle of themselves, we may certainly conclude, That there is a congruity betwixt them, in some respect or other. So upon various trials I find, that Essential Oils do more easily imbibe an Acid, than an Alkaly. Whence it is evident, That there is some congruity and similitude betwixt Essential Oils, and an Acid, which there is not betwixt the said Oils and an Alkaly.  
As to those that mingle only by some third; we may also certainly conclude, That though the two extremes are unlike; yet that they have both of them a similitude to or congruity with that third, by which they are united.  
Moreover, We may make a Judgement from the Manner or Degree of Mixture. Thus the Acid Spirit of Nitre, as is said, will coagulate oil-olive, and render it consistent. Whence it might be thought, That any other strong Acid will do the like; and that therefore, there is no great difference in the Nature of the said Acid Liquors. But the contrary hereunto, is proved by Experiment. For having digested the same Oil, in the same manner, and for a much longer time, with strong Oil of Sulphur; although it thence acquired some change of Colour, yet not any Consistence.  
Again, Because the said Spirit of Nitre coagulates oil-olive; it might be expected, it should have the same effect, upon Oil of Aniseeds; or, at least, that if other Acids will coagulate Oil of Aniseeds, that this should do it best. But Experiment proveth the contrary. For of all I have tried, Oil of Vitriol is the only Acid that doth it instantaneously. Oil of Sulphur, if very strong, will do it; but not so soon, nor so much. Aqua fortis, and Spirit of Salt, for the present, do not at all touch it. And Spirit of Nitre itself will not coagulate it, under eight or ten hours at least.   

Instance VI.  
LASTLY, and consequently, It is a Key, To Discover the Medicinal Use and Operation of Bodies. Thus, for example, by the Imitation of Rosins and Resinous Gums, we certainly know what all of them are, and when, and wherefore to be used▪ For what are Mastic, Frankincense, Olibanum, Benzoin, and other like Rosins, or Resinous Gums, for their principal and predominant parts, that is, qua Rosins; but Bodies resulting from Natural, in like manner, as I have showed, they may be made to result, from Artificial Mixture? That is to say, the Oleous, and Acid parts of Vegetables, being both affused and mingled together, per minima, in some one Vessel of a Plant, they thus incorporate into one consistent and friable body, which we call Rosin.  
Now from hence it is, that the said Rosins, and Resinous Gums; as also Amber and Sulphur for the same reasons; are of so great and effectual Use against most thin and salted Rheums; sc. as they are Acido-oleous Bodies▪ For by their Acid parts, which in all these Bodies are exceeding copious, they mortify and refract those salt ones which feed the Rheum. And by their oleous parts, the same salt ones are also Imbibed. Whence, they are all, in some degree, incorporated together; that is, the Rheum is thickened: which is the desired effect.  
Whereas, on the contrary, if the Cough proceed not from a thin and especially a salt Rheum, but from a Viscous Phlegm; the use of many other Bodies, which are also more oleous, and abound not so much with an Acid as these do, especially some of them, is more proper: such as these, in this case, proving sometimes not only ineffectual, but prejudicial. Since the very Cause of the said Viscousness of Phlegm, is chiefly some great Acidity in the Blood, or in some other part; as may be proved by divers arguments.  
Many more Instances might be hereunto subjoined: and may hereafter be offered to the acceptance of such, who are inquisitive into matters of this Nature. If I shall not herein anticipate, or reiterate the Thoughts and Observations, of those two accurate and Learned Persons Dr. Willis, and Dr. Walter Needham, as to what the one hath already published, and both have put us in expectation of. But the Instances already given, are sufficient to evidence what I have said. And, I hope, this present Discourse to prove, in some measure, thus much; That Experiment, and the Common Notions of Sense are prolific; and that nothing is barren, but fancy and imagination.  
FINIS.