216 PROCEEDINGS OF THE AMERICAN ACADEMY. 



dissolved all but a slight black residue. On allowing the benzol solu- 

 tion to evaporate a crystalline substance was obtained, which was puri- 

 fied by crystallizations with the aid of bone-black at first from water 

 mixed with a little alcohol, finally from water alone, until it showed 

 the constant melting point 153°, when it was dried at 100°, and ana- 

 lyzed with the following results: — 



I. 0.2353 gram of the substance gave on combustion 0.4931 gram of 

 carbonic dioxide and 0.08G2 gram of water. 

 II. 0.1454 gram of substance gave by the method of Carius 0.1418 

 gram of baric sulphate. 



Found. 



II 



13.39 



As this body must be a substituted pyrocatechine, it should give a 

 lead salt, and upon trying it with a solution of plumbic acetate we 

 obtained one, which was analyzed with the following result : — 



0.2601 gram of the substance gave 0.1729 gram of plumbic sulphate. 



Calculated for ifniiiifl 



Lead 45.50 45.39 



There can be no doubt, thei-efore, that the substance is a pyrocate- 

 chinesulphone or orthodioxydiphenylsulphone. 



Properties of Orthodioxydiphenylsulphone, C6H3(OH)oS02CgHj. — It 

 crystallizes from alcohol and water in short, thick, well-formed, white 

 prisms terminated by two planes at an obtuse angle to each other. 

 It contains no water of crystallization, and melts at 153°. It is 

 easily soluble in alcohol, ether, chloroform, or glacial acetic acid ; 

 very slightly soluble in cold water, or benzol, freely soluble in either 

 of these liquids when hot; essentially insoluble in ligroin, either hot or 

 cold. Alkalies dissolve it with a yellow color. Ferric chloride gives a 

 bluish green color with it, which changes to red on the addition of 

 sodic carbonate. As has been already mentioned, its aqueous solution 

 gives a precipitate with plumbic acetate. 



This substance has the same composition as the orthodioxydiphenyl- 

 sulphone made by Hinsberg and Himmelschein * by oxidizing pyrocate- 



* Ber. d. chcm. Ges. XXIX. 2025. 



