( ) 
Heat, Fire, and Gun powder, and feveral other 'Phxno- 
mn a } which feem ro be mort prodigious and wonderful 
in Nature. A^d fince the Experiment feem’d fo conrt- 
derable, as to account for feveral furprizing Operations 
in Nature, I thought it very worthy an Examination, by 
a Repetition cf the fame. 
Accordingly I procur’d a Bolt-Head (Tuch as he there 
defcribesj with a long fmall Stem, which I fill’d nearly 
full of common Water. The Stem was mark’d into feve- 
ral Divifions, on a piece of Paper parted along it 5 by 
which means, I diligently obferv’d the heigrh of the 
Surface of the Water. Then pouring as much of it out 
as fill’d a certain Meafure, which being thrown away, I 
fill’d the fime Meafure, as nicely as portable, to the fame 
height, with ftrong Oil of Vitriol * which I return’d in- 
to the Bolt- Head, in the room of fo much Water taken 
from thence.- Upon the mixing of thcfe Liquors en- 
fued a pretty vftrong Ebullition , and abundance of airy 
Particles were vifibly extricated, and the Surface was not 
fo high in. the. Stem confiJerably, as when ir was poflTeft 
only by Water. But here I muft take notice, that two or 
or three Drops of Oil of Vitriol were accidentally fpilr, 
in putting it into the bolt Head ^ but yet the Experiment 
was very manifeft, in the gradual decreafe of the Dimen' 
fions cf the Liquors. # And ’tis to be obferved, that 
altho’ they became very warm, yet, contrary to the Na- 
ture of moft Liquors in fuch a State, they continued to 
poflefs lefs and lefs fpace ; which was vifible by the fink- 
ing of the Surface in the Stem of the Bolt-Head 5 and 
in about half an Hours time, it had defeended above 
an Inch: And when I vificed it on th z. Monday follow-' 
ing (for the Experiment was made on the Ihnrfday) I 
found it had fubfided at leaft two Inches below the mark 
I had left it at. Now whether the Ebullition produced 
by the Heat, might not evaporate that quantity, which 
it feetii’d to lofe in fpace 5 or whether, in fo many Hours 
time, 
