The works of the Honourable Robert Boyle, Esq., epitomiz'd by Richard Boulton ... ; illustrated with copper plates.

EXPERIMENT VI.

* 1.1TO try how much the Air was capable of being expanded, we fix'd the Neck of a wet Lamb's Bladder to the Neck of a Viol; which being conveigh'd into the Pneumatical Receiver, upon the Exsuction of the Air, we observ'd, that

the Air which was contain'd in the Cavity of the Viol was so far expanded, that tho' the Viol was able to contain above five Drachms of Wa∣ter, if filled and distended the empty Bladder, which was large enough to hold five Ounces and half a Drachm. In which Experiment, the ex∣panded Air possessed nine times as much space as it did before Expansion.

But to measure the Air's Expansion more nicely, we fix'd a Glass Bubble to one end of a Cylindrical Pipe, hermetically sealed; the Di∣ameter of whose Bore was about a quarter of an Inch; and having pasted a Piece of Parch∣ment upon the outside of the Tube, which was divided into twenty six equal Parts, and mark'd with black Lines, we fill'd the Cylinder almost full of Water, so that, after a few Tryals, by inverting the Cylinder, and stopping the open End with one's Finger, we could perceive, that as much Air might be permitted to rise up to the Bubble, as was equal in Extension to the Breadth of one of those twenty six Divisions; When this was done we fitted the open end of the Cylinder to a Glass Viol, which was fill'd with Water to the Height of half an Inch; all which being put together into a Pneumatical Re∣ceiver, after a few Exsuctions, the included Air was so much expanded, as to extend it self to the Surface of the Water; in which Expe∣riment the expanded Air took up thirty one times as much Space as before.

And this Experiment being repeated in a Cy∣linder, which afforded a larger space for the Air's Expansion, it took up above sixty times the space it did before. And repeating the like Ex∣periment

with a Glass Pipe thirty Inches long (part of it having a Hole in the Cover to stand out through) by weighing the Water in a nice Pair of Scales together with the Pipe, first with the Bubble of Air included, and after when the Tube was wholly filled with Water, we found, That the Air which possessed but the Space of one Grain of Water had been expanded, in the exhausted Receiver so much by its own 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, as to take up 152 times its Space before Extension.

And since Marcennus affirms, That the Air may be so expanded by Heat, as to take up seventy times its Space, I conveyed a Cylinder of the former Magnitude into the Receiver, and found, That upon the Exsuction of the Air in the Receiver, that in the Cylinder descended down almost to the bottom of it, the lower Surface of it being very convex, and seeming several times to knock upon, and re∣bound from the bottom of the Viol; which was an Argument of the expansive Force of the Air; since the Water it depressed, upon the drawing out of the Air, was much below the Surface of the Water contain'd in the Viol.

Notes

• * 1.1

  The Airs Expansion measur'd.