1884.] on Liquefied Gases. 153 



experiments on the density of liquid carbonic acid obtained from 

 mixtures of this body with these gases. At the temperature of 0° C. 

 the experiments found for oxygen, nitrogen, and hydrogen the 

 respective values of * 65, • 37, and * 025. It seems that the calculated 

 values for oxygen and nitrogen are not very far wrong ; but hydrogen 

 is clearly incorrect. The explanation of this anomaly is probably to 

 be found in the fact that the calculated molecular volume of hydrogen 

 is wrong, and that instead of being unity on our scale it ought to be 

 3 • 5 like oxygen and nitrogen. In fact, the chemist would infer that, 

 as the difference in the complexity of the molecular structure of 

 hydrochloric acid, water, ammonia, and marsh-gas does not affect the 

 molecular volume under the coLditions we are discussing, in all 

 probability the value for hydrogen would be identical with that of the 

 above-mentioned bodies. If we adopt this view and change the value 

 of the T,-J-Pc to 3-5, then the density of the fluid would become • 034, 

 which is in accordance with the experimental number of Cailletet and 

 Hautefeuille. An accurate determination of the critical temperature 

 and pressure of hydrogen, for which, judging from the success of the 

 experiments of M. Olzewski, chemists will not have to wait long, will 

 thus be of great interest. 



[J.D.] 



GENERAL MONTHLY MEETING, 



Monday, July 7, 1884. 



The Hon. Sir William R. Grove, M.A. D.C.L. LL.D. F.R.S. 

 Manager and Vice-President, in the Chair. 



James Wimnshurst, Esq. 



was elected a Member of the Eoyal Institution. 



The decease of The Right Hon. Lord Claud Hamilton, a Manager, 

 was announced from the Chair. 



The Managers, at their Meeting this day, appointed Professor 

 Arthur Gamgee, M.D. F.R.S. Fullerian Professor of Physiology for 

 three years. 



