BODIES GENERALLY EXISTING AS GASES. lyj 



The following g^ses showed no signs of liquefaction when cooled by the carbonic 

 acid bath in vacuo, even at the pressures expressed : — 



Atmospheres. 

 Hydrogen at ..... 27 



Oxygen at 27 



Nitrogen at 50 



Nitric oxide at 50 



Carbonic oxide at . . . .40 

 Coal gas 32 



The difference in the facility of leakage was one reason of the difference in the press- 

 ure applied. I found it impossible, from this cause, to raise the pressure of hydroo-en 

 higher than twenty-seven atmospheres by an apparatus that was quite tight enouo-h 

 to confine nitrogen up to double that pressure. 



M. Cagniard de la Tour has shown that at a certain temperature, a liquid, under 

 sufficient pressure, becomes clear transparent vapour or gas, having the same bulk as 

 the liquid. At this temperature, or one a little higher, it is not likely that any increase 

 of pressure, except perhaps one exceedingly great, would convert the gas into a liquid. 

 Now the temperature of 166° below 0°, low as it is, is probably above this point of 

 temperature for hydrogen, and perhaps for nitrogen and oxygen, and then no com- 

 pression without the conjoint application of a degree of cold below that we have as 

 yet obtained, can be expected to take from them their gaseous state. Further, as ether 

 assumes this state before the pressure of its vapour has acquired thirty-eight atmo- 

 spheres, it is more than probable that gases which can resist the pressure of from 

 twenty-seven to fifty atmospheres at a temperature of 166° below 0° could never ap- 

 pear as liquids, or be made to lose their gaseous state at common temperatures. 

 They may probably be brought into the state of very condensed gases, but not 

 liquefied. 



Some very interesting experiments on the compression of gases have been made 

 by M. G. AiME*, in which oxygen, defiant, nitric oxide, carbonic oxide, fluosilicon, 

 hydrogen, and nitrogen gases were submitted to pressures, rising up to 220 atmo» 

 spheres in the case of the two last ; but this was in the depths of the sea where the 

 results under pressure could not be examined. Several of them were diminished in 

 bulk in a ratio far greater than the pressure put upon them ; but both M. Cagniard 

 DE LA Tour and M. Thilorier have shown that this is often the case whilst the sub- 

 stance retains the gaseous form. It is possible that defiant gas and fluosilicon may 

 have liquefied down below, but they have not yet been seen in the liquid state except 

 in my own experiments, and in them not at temperatures above 40° Faftr. The re- 

 sults with oxygen are so unsteady and contradictory as to cause doubt in regard to 

 those obtained with the other gases by the same process. 



Thus, though as yet I have not condensed oxygen, hydrogen, or nitrogen, the ori- 



* Annales de Chimie, 1843, riii. 275. 

 z2 



