water by high degrees of force. 545 
I next applied the apparatus to the compression of aeriform 
fluids. 
A gasometer B, was filled half full of water ; it was then 
inverted, and placed in receiving tube A, as represented in 
fig. 8 : it was found that, under a pressure of 500 atmospheres, 
the whole of the air was taken up by the water ; but none of 
it was given out when the pressure was taken off. 
As it might be supposed that even glass was pervious to 
water by such a force, a small phial was made air-tight, by 
fitting into its neck a well-ground glass stopper. It sustained 
pressure of 500 atmospheres without change, and was per- 
fectly dry within, although it remained under that pressure 
1 5 minutes. It was next subjected to a pressure of 800 at- 
mospheres, and when taken out was found to be crushed to 
atoms. 
In the course of my experiments on the compression of 
atmospheric air, by the same apparatus which had been used 
for compressing water, I observed a curious fact, which in- 
duced me to extend the experiment ; viz. that of the air 
beginning to disappear at a pressure of 500 atmospheres, 
evidently by partial liquefaction, which is indicated by the 
quicksilver not settling down to a level with its surface. At an 
increased pressure of 600 atmospheres, the quicksilver was sus- 
pended about -g- of the volume up the tube or gasometer ; at 
800 atmospheres, it remained about i up the tube ; at 1000 
atmospheres, ~ up the tube, and small globules of liquid began 
to form about the top of it ; at 1200 atmospheres, the quick- 
silver remained J- up the tube, and a beautiful transparent 
liquid was seen on the surface of the quicksilver, in quantity 
about 20 I 00 part of the column of air. The gasometer, fig. 9, 
