48 PROCEEDINGS OF THE AMERICAN ACADEMY. 



0.4671 gram of the substance, after treatment with amnionic hydrate, 

 gave 0.1417 gram of baric sulphate. 



Calculated for (C6H2Br3NH2)2H2S04. Found. 



SO4 12.66 12.49 



Properties. — The salt crystallizes from dilute sulphuric acid in broad 

 white shining [)lates, which are soluble in water ; but if its aqueous solu- 

 tion is heated, it decomposes partially into the tribromaniline and sul- 

 phuric acid. In the presence of a little sulphuric acid, on the other hand, 

 the aqueous solution can be heated without decomposition. The salt is 

 soluble in alcohol, and its solubility is increased by heat ; insoluble in 

 benzol, chloroform, or ether. 



Tribromphenylurethane, CeH.^BrgNHCOOCoHs, NFI l,Br3 3, 4, 5. 



This substance was prepared by boiling a benzol solution of ten grams 

 of the tribromaniline with eight grams of chlorocarboiiic ethyl ester in a 

 flask with a return condenser. After heating for five hours, as no more 

 hydrochloric acid was given off, the mixture was allowed to cool, when 

 crystals appeared, which were filtered out, and crystallized from dilute 

 alcohol until they showed the constant melting point 1 69°-170°. The sub- 

 stance was then dried at 100°, and analyzed with the following results : — 



I. 0.1915 gram of the substance gave 0.2708 gram of argentic bromide 



by the method of Carius. 

 II. 0.1771 gram of the substance gave 0.2473 gram of argentic bro- 

 mide by the method of Carius. 



Calculated for Found. 



CBHoBrsNHCOOCoHg. I. 11. 



Bromine 59.70 60.20 59.43 



The NH2l5 Bi-g 2, 4, 6 tribromaniline gives no urethane under these 

 conditions. 



Properties. — This tribromphenylurethane crystallizes from a mixture 

 of alcohol and water in thin white rhombic plates frequently with the 

 acute angles bevelled by two other planes makin;^ a very obtuse angle 

 with the sides of the original rhomb. It melts at 169°-170°; and is 

 easily soluble in alcohol, ether, benzol, or chloroform ; essentially in- 

 soluble in cold ligroin, soluble in hot. Strong hydrochloric acid in the 

 cold has no apparent action on it. Strong nitric acid or strong sulphuric 



