90 PROCEEDINGS OP THE AMERICAN ACADEMY 



Parabromhenzylsulphone, {C^fivCYi^.^Oc^, was made from the sul- 

 phide by dissolving it iu glacial acetic acid, and adding the calculated 

 amount of chromic anhydride also dissolved in glacial acetic acid. 

 After the action had ceased, the substance was precipitated with water, 

 and purified by crystallization from alcohol. It was analyzed after 

 drying at 100°. 



0.1674 g. of substance gave by the method of Carius 0.1556 g. of 

 argentic bromide and 0.0991 g. of baric sulphate. 



It crystallizes in white needles, with a slight not unpleasant smell ■; 

 melts at 189°, and is essentially insoluble in water, soluble only to a 

 slight extent in cold alcohol, benzol, ligroine, and glacial acetic acid, 

 freely soluble in all these solvents when hot, and in ether and carbonic 

 disulphide whether cold or hot. 



Parabromhenzylmercaptan, CgH^BrCHgvSII. 



This substance was made by the action of parabrombenzylbromide 

 on an alcoholic solution of potassic sulphydrate. The action took 

 place very easily, and the product fell as an oil on the addition of 

 water to the alcoholic solution. It was purified by distillation with 

 steam, and solidified to a white crystalline mass after standing some 

 time. It bad a disagreeable odoi*, and melted at 25°, but we cannot 

 be perfectly certain that this is the true melting-point, on account of 

 its strong tendency to pass into the disulphide on exposure to the air. 

 The number given above, however, cannot be far from the correct one, 

 as the sample was treated with zinc and sulphuric acid immediately 

 before taking the melting-point. It dissolves easily in all the common 

 solvents with the exception of water and glacial acetic acid. It did 

 not seem worth while to analyze the free mercaptan, as the results 

 obtained from it are almost identical with those from its principal im- 

 purity, the disulphide ; but instead of this, we determined its nature 

 much more satisfactorily by converting it into the mercaptid, which 

 was then analyzed. 



Parabrombenzylmercaptid, (C^^YCYi^^).^^. 



This substance was made by adding yellow mercuric oxide to the 

 mercaptan suspended in water ; after the action had ceased, the insolu- 



