450 



Messrs. D. Mcintosh and B. D. Steele. [Apr. 26, 



" On the Liquefied Hydrides of Phosphorus, Sulphur, and the 

 Halogens, as Conducting Solvents. — Part I." By D. McIntosh 

 and B. D. Steele. Communicated by Sir William Bamsay, 

 K.C.B., F.R.S. Received April 26,— Read May 19, 1904, 



Ammonia, water, and hydrofluoric acid, are the only hydrides of the 

 elements which have been systematically investigated with respect to 

 their solvent properties, and in particular with respect to their power 

 of forming electrically conducting solutions. With the object of 

 extending our knowledge of the properties of these hydrogen 

 compounds, when liquefied, and in the hope that more light might 

 thereby be thrown on the question of ionic dissociation, the investiga- 

 tion, of which this is a brief abstract, has been undertaken. 



The following hydrides of the fifth, sixth, and seventh groups have 

 been examined, hydrogen phosphide, sulphide, chloride, bromide, and 

 iodide. Since it had been found by preliminary experiments that, 

 with the exception of hydrogen phosphide, all these possessed the 

 power of conducting the current when certain substances were 

 dissolved in them, a number of physical constants were measured 

 before proceeding to the systematic study of the conductivity of 

 solutions. 



A brief summary of the results found hitherto is contained in the 

 following tables, in which the temperatures are given to the nearest- 

 tenth of a degree. 



These were determined by the method described by Travers, Senter, 

 and Jaquerod,* and used by them for the measurement of the vapour 

 pressures of liquid oxygen and hydrogen. 



1. — The Vapour Pressure Curves. 



Hydrochloric Acid. 



T. 



P. 

 141-0 

 198-0 

 245-0 



T. P. 



T. 



P. 



648 

 748 

 868 



-109-9 

 - 104-5 

 -101-3 



-97-2 316-0 

 - 92-9 430-0 

 -89-8 522-0 



85-9 

 83-2 

 80-5 



Hydrobromic Acid. 



- 104-2 

 -100-7 



- 96-3 



- 92-8 



96-0 

 142-0 

 185-0 

 214-0 



-89-3 245-0 



-87-1 284-0 



- 83-0 357-0 



-79-3 431-5 



76-7 

 74-0 

 70-7 

 68-4 



501 

 575 

 682 

 775 



* ' Phil. Trans.,' A, 1902, toI. 200, p. 138. 



