Tracts written by the Honourable Robert Boyle containing New experiments, touching the relation betwixt flame and air, and about explosions, an hydrostatical discourse occasion'd by some objections of Dr. Henry More against some explications of new experiments made by the author of these tracts : to which is annex't, An hydrostatical letter, dilucidating an experiment about a way of weighing water in water, new experiments, of the positive or relative levity of bodies under water, of the air's spring on bodies under water, about the differing pressure of heavy solids and fluids.

EXPER. III. About an Explosion made by two Bodies actually Cold.

I Remember not, that I found the Assertors of Explosions in Animals to have taken notice of a difficulty, which to me seems not uneasie to be observ'd, and yet very worthy to be cleared. For 'tis known, that Fishes, and those especially of the vaster sort, can move and act in the waters with a stupendious force; and yet it is affirm'd by those that pre∣tend to know it, that the Blood of most Fishes is still actually cold:

And I remember, I found the blood even of those I dissected alive, to be so. From whence most men would argue, that even in the vast Sea-monsters, there can be made no Explosions, these being still effe∣cted by or accompanied with an in∣tense degree of heat.

'Twere incongruous to my de∣sign, to examine this difficulty as it directly regards the Explosions, said to be made in Animals: But speak∣ing of Explosions in general, per∣haps I might do the favourers of vital ones (if I may so term them) no unacceptable piece of service, by ex∣perimentally shewing, that 'tis not impossible, though it seem very un∣likely, that Explosions should be made upon the mixture of bodies, which, whilst they seem to put one another into a state of Effervescence,

are really cold, nay colder than be∣fore their being mingled. Of these odd kind of mixtures, I remember I have in another paper set down some Tryals that I made to other pur∣poses, as well with two liquors as with a liquor and a solid body; which later sort I there mention my having made by an improvement of an experiment of the excellent Florentine Virtuosi. And among those Tryals I find one, whose per∣tinency to the matter in hand invites me to annex as much of it as is proper in this place.

There were put two ounces of powder'd Sal Armoniac into a pret∣ty large Glass-tube Hermetically seal'd at one end; into the same a slender Glass-pipe, furnished with two ounces of Oyl of Vitriol, was

so put, that, when we pleas'd, we could make the liquor run out into the larger Tube, which, after these things were done, was clos'd ex∣actly, so that nothing might get in or out. My design was, that this instrument should be so warily inverted, that the Operator might get out of the way, and the Oyl of Vitriol, falling slowly upon the Sal Armoniac, should, without produ∣cing any heat, produce an explo∣sion not dangerous to the By-stan∣ders. But whilst I was withdrawn to a neighbouring place to write a Letter, the Operator not staying for particular directions, rashly inverted the instrument without taking care to get away: whence it happen'd, that as soon as ever the contained liquor, being too plentifully poured out, came to work on the Sal Armo∣niac,

wherewith it is wont to pro∣duce cold, there was so surprizing and vehement an Expansion or Ex∣plosion made, that with a great noise, (which, as the Laborant af∣firmed, much exceeded the report of a Pistol,) the Glasses were broken into a multitude of pieces, many of which I saw presently after, and a pretty deal of the mixture was thrown up with violence against the Operators Doublet and his Hat, which it struck, off, and his face; especially about his eyes, where im∣mediately were produc'd extreamly painful tumors, which might also have been very dangerous, had I not come timely in, and (to add that upon the by) made him forth∣with dissolve some Saccharum Sa∣turni in fair water, and with a soft spunge keep it constantly moisten'd

by very frequently renewed appli∣cations of the Liquor: By Gods blessing upon which means, within an hour or two, the pain, that had been so raging, was taken away, and the fretting Oyl of Vitriol was kept from so much as breaking the skin of the Tumors that it had made.

The first part of the Relation of this tryal might have been omitted, or at least shorten'd, unless I had design'd to communicate unto you a way of doing what I do not know to have been attempted by others, namely to put bodies together when and by what degrees one pleases, after the Glass that contains them has been Hermetically seal'd up; which Mechanical contrivance, e∣specially as it may be varied, may be, as I have try'd, use∣fully

apply'd to more purposes than 'twere proper here to take no∣tice of.

But to conclude with a word or two touching the foregoing Expe∣riment; I shall only add, That a∣nother time we made a like tryal a safer way, by tying a Bladder so to the top of a Bolt-head, into which we had before-hand put the Sal Armoniac, that, by warily mo∣ving the Bladder, whence the Air had been express'd, we could make some of the Sal Armoniac, we had lodg'd in its folds, to fall upon the liquor, with which it presently made an Explosive mixture, that quickly blew up the Bladder.

But these, Sir, are bare Conje∣ctures, left to be, after a farther discussion, (if you think them wor∣thy

of it) determin'd by You, to whom as these Papers are address'd, so they are also submitted by the Writer of them,

Who is Sir

Your most, &c.

Notes

• About the Pre∣duction or Extri∣cation of Air.