2 Jones, Selenimn and Tcllurimn on Arsine and Stibine. 



It appeared probable that the elements selenium and 

 tellurium, which are analogous to sulphur, would act in a 

 similar way with arsine and stibine and I have now to 

 record the results of experiments made to decide this 

 question. 



In the course of these experiments it was necessary to 

 have distinguishing tests for the hydrides of sulphur, 

 selenium and tellurium which are so alike in their 

 reactions. Each of these hydrides produces on paper 

 moistened with solution of lead acetate, dark stains which 

 are extremely similar, and I was unable to find any tests 

 recorded which would serve to distinguish them. On 

 trying the effect of various reagents upon these stains I 

 found that hydrogen dioxide and hydrochloric acid were 

 useful for this purpose, at all events in the case of a 

 distinct stain. The differences in the behaviour of these 

 stains with reasfents are shown in the following table : — 



These reaction.? were employed to discriminate 

 between the lead stains obtained in the course of the 



