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 pari- 

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

 mixed with a little alcohol, finally bom water alone, until it Bhowed 

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

 lyzed with the following results: — 



I. 0.2o5o gram of the substance gave on combustion 0.4931 gram of 

 carbonic dioxide and ".<iSG2 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 Bait, 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 _ ,_, 



C c lI 3 O.,t>uS0,»', II... * 0aUd - 



Lead 45.50 45.39 



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

 chinesulphone or orthodioxydiphenj lsulphone. 



Properties of Orthodipxydiphenyhidpkone, C 6 Hg(OH) 2 SO s C a tT 5 . — It 

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

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

 It contains no water of crystallization, and melts at 158°. It is 

 ily Boluble in alcohol, ether, chloroform, or glacial acetic acid; 

 \.-rv Blightly soluble in cold water, or benzol, freelj Boluble 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 tin- addition of 



>odic carbonate. A- has been already mentioned, its aqueous solution 

 gives a precipitate with plumbic acetate. 



This Bubstance has the Bame composition a- the orthodioxydiphenyl- 

 Bulphone made by Hinsberg and Eiimmelschein * by oxidizing pyrocate- 



• Ber. <1. dam Gei \\l\ 202 



