ox NITUOUS OXTDE IN THE GASEOUS AND LIQUID STATES^. 



213 



Those results agree closely with the experiments of Dr. Andrews at the cor- 

 respoudiug temperatures, tlie differences being ouly 0*2 of an atmosiihere. At 

 21°-47 the gas passed into the liquid state at a pressure of GO'S atmospheres, 

 whilst its volume had diminished from 17,000 to 162 ; with Dr. Andrews 

 this pressure amounted to GO'05 atmospheres, and the corresponding volume 

 of the carbonic acid to 160. As the quantity of air in my case was about 

 ^^ of the entire volume of the gas, the increase of pressure to liquefy the 

 whole after liquefaction had begun, amounted to about 2-4 atmospheres, viz. 

 from 59'81 to 62-18. The critical temperature I found to be 30°-87. It 

 wUl be observed that the pressures are those indicated by the apparent con- 

 traction of the air in the air-tube. 



In the following Tables ^ and e have the same meaning as before, but ap- 

 plied to nitrous oxide ; I, however, represents the number of volumes which 

 1000 volumes of nitrous oxide, measured at 0° and 760 millims., would oc- 

 cupy at the temperature and pressure of the observation. The experiments 

 ■were made at the temperatures of 25''-15, 32°-2, 36°-4, 3S°-4, and 43°-8, two 

 series below, and three above, the critical point, which was found to vary 

 between 36'^-3 and 36°-7. The appearances were the same as with carbonic 

 acid. 



Table I. — Nitrous Oxide at 25--1.5. 



