Chemistry. — ''On an Indirect Anahjsis of Gas-Hydrates hy a 

 Thermodynamic Method and Its Application to the Hydrate 

 of Sulphuretted Hydrogen:' I. By Prof. V. E. C. Schkpfkr 

 and G. Meyer. (Coininiinieated by Prof. Bökskkkn). 



(Communicated in the meeting of February 22, J 919). 



I. In two papers one of us has given an extensive description of 

 heterogeneons equilibria in the system sulphuretted hydrogen-water '). 

 It has appeared in this investigation that through the appearance 

 of a compound and through unmixing in the liquid state a four- 

 phase equilibi'ium hydrate of sulphuretted hydrogen - two liquid 

 layers - gas occurs in this system; the three-phase-lines which 

 intersect in this quadruple point, were determined, and besides 

 a number of analyses was carried out to get to know the composition 

 of the hydrate. These analyses, however, yielded very different 

 results; the number of molecules of water which is bound with one 

 molecule of sulphuretted hydrogen varies between 5,1 and 5,5 accord- 

 ing to these determinations. This result led to the conclusion that 

 the formula of the hydrate would be H,S . 5H,0, because for this 

 substance, and for gas hydrates in general a phenomenon occurs 

 that causes the water content on analysis to be found too high. 

 When we consider that the two liquid layers consist almost of [)ure 

 sulphuretted hydrogen, resp. pure water, and that therefore, the 

 hydrate must be formed by cooperation of the two liquid layers, it 

 is clear that this formation of hydrate gives rise to a separation of 

 the layers on the boundary of the liquids. In analyses an excess of 

 sulphuretted hydrogen was always used, which was pumped off 

 after action of the liquid layers. It is clear that when this excess 

 of sulphuretted hydrogen has been removed, water can be left behind 

 in the solid substance, as this possesses hardly any tension at low 

 temperature as ice; this is accordingly the reason that formerly 

 always lower values were found for the water content as more care 

 was devoted to the interaction of the layers. Chronologically arranged 

 the analyses yielded water contents of 15'), 12') and 7 ') molecules 



1) These Proceedings. 13. 829 (1911) and 14. 195 (1911). 



2) De Forcrand. C.r. 94. 967. (1882). 



2) De Forcrand. Ann. chim. phys. (5). 28. 5. (1883). 

 *) De Forcrand and Villard. C.r. 106. 1402. (1888). 



