546 Mr. Perkins on the progressive compression of 
was at another time charged with carburetted hydrogen, and 
placed in the receiving tube A, fig. 8, with its mouth im- 
mersed in the quicksilver C ; it was subjected to different 
pressures, and it began to liquefy at about 40 atmospheres, 
and at 1200 atmospheres the whole was liquefied. 
These instances of apparent condensation of gaseous fluids 
were first observed in January, 1822 ; but for want of chy- 
mical knowledge requisite to ascertain the exact nature of 
the liquids produced, I did not pursue the inquiry further ; 
and as the subject has been taken up by those who are 
eminently qualified for the investigation, I need not regret 
my inability to make full advantage of the power I had the 
means of applying. 
I have been desirous of ascertaining the law of condensa- 
tion of gaseous fluids, at the high degrees of pressure ; but 
as the apparatus for the compression of water, which requires 
to be made sensible at its lower extremity, is by no means 
adapted to show the higher degrees of compression of gases, 
a suitable apparatus requires to be made for such experi- 
ments ; which I shall hope to make the subject of a future 
communication. 
