ON THE HALOGEN HYDRIDES AS CONDUCTING SOLVENTS. 137 



These results may be briefly summarised as follows : 



Toluene, which is a non-conductor in each of the solvents, has an average molecular 

 weight of about 30 in hydrogen chloride, 78 in hydrogen bromide, and about 90 in 

 sulphuretted hydrogen, and therefore appears to be dissociated when dissolved in 

 hydrogen chloride and hydrogen bromide and to a greater extent in the former 

 solvent. 



KAHLENBERG ('Jour, of Phys. Chem.,' 1901, v., 344; 1902, vi., 48) has noticed a 

 similar anomaly in the case of a solution of diphenylamine in methyl cyanide. 



Ether in hydrogen chloride and hydrogen bromide, and acetone in hydrogen 

 bromide have molecular weights which indicate association in the more dilute solvents 

 and dissociation in the more concentrated. 



Triethylamine hydrochloride appears to be dissociated when dissolved in sulphur- 

 etted hydrogen, the dissociation being greater in the more concentrated solutions. 



VOL. COV. A. 



