﻿324 Mr. Baly and Dr. Ramsay on the Relations of Pressure, 



which are of the same volume within *1 per cent., gave values 

 of joy which instead of being equal had a ratio to one another 

 of 1 to 8*8. We give the values : — 



Gauge E. 



Gauge F. 



p. pv. 



p. pv. 



12-3 = 6-00 



100 = 53-3 



17-9 = 6-04 



106-1 = 53-1 



25-6 = 6-09 



113-3 = 530 



37-5 = 6-03 



125 = 53-2 



6-04 53-15 



A large number of experiments were made, in which the 

 gauges were continually opened and again closed and read, 

 but the right ratio was not obtained until after 78 hours' rest. 

 Then the readings in the gauge became normal, and an 

 experiment was attempted to measure the coefficient of 

 expansion, but the equilibrium of the gas was instantly dis- 

 turbed, and the result came out about ~^. When the ap- 

 paratus was exhausted beyond this particular point, the 

 behaviour of the gas became quite regular again, and two 

 measurements of expansion were made. This same anomaly 

 was met with again in subsequent experiments. 



The coefficients of expansion of oxygen we obtained were 

 as follows : — 



5*1 millim. 



5-3 „ 



4-0 „ 



2-5 



1-4 „ 



•083 „ 



•07 „ 



261' 



262' 



(i 



^250-i* 

 J_ 

 233* 



2W 



1 

 240-3* 



T. 



132-11 



t. 



o 



11 



132-0 



11 



131-6 



13 



132-1 



9-4 



131-8 



11-5 



132-15 



10-9 



131-71 



9-1 



131-84 



11 



It will be seen, therefore, that the coefficient of expansion 

 of oxygen decreases with decrease of pressure. Having a 

 value of about ^ at 5 millim., it increases steadily to where 

 the change takes place. At a rarefaction greater than at this 

 point, the value of the coefficient is again smaller, but it still 

 appears to increase with further diminution of pressure. 



It is difficult to account for the abnormal behaviour of 

 oxygen as regards distribution in the gauges at a pressure of 



