106 PROCEEDINGS OF THE AMERICAN ACADEMY 



was partially precipitated as an oily liquid, and more of the oil was 

 obtaiued by extracting" the solution with ether. The residue left by 

 evaporation of the ether was immediately converted into the carbonate 

 by absorbing carbonic dioxide from the air. It was dissolved in 

 alcohol, a little hydrochloric acid added, and the platinum salt formed 

 by the addition of chlorplatinic acid. This salt crystallized in pale 

 yellow microscopic prisms, which were sparingly soluble in water and 

 cold alcohol, readily in hot, and insoluble in ether. It was purified by 

 recrystallization from hot alcohol, washed with ether, and dried over 

 sulphuric acid for analysis. 



0.2082 grm. of the salt gave on ignition 0.0468 grm. platinum. 



Calculated for (C7lIJNH3)2PtCl6 . Found. 



Pt 22.48 22.48 



Since our work was interrupted by the closing of the summer term, 

 a more complete examination of the derivatives of orthoiodbenzyl- 

 bromide must be reserved for another paper. 



CHLORTEIBROMPROPIOKIC ACID. 

 Charles F. Mabery and H. C. Weber. 



The formation of chlortribrompropionic acid by the action of bro- 

 mine on chlorbromacrylic acid has been mentioned in a previous paper 

 by R. Lloyd and one of us.* Although this reaction took place with- 

 out difficulty in a chloroform solution at ordinary temperatures, the 

 product proved to consist in great part of an oil which could not be 

 made to crystallize. With the hope of obtaining a more satisfactory 

 yield we tried the action of undiluted bromine at a higlier tempera- 

 ture. Chlorbromacrylic acid, melting point 68-70°, with a slight 

 excess over the calculated weight of bromine, was heated to 100° for 

 two hours in a closed tube. The excess of bromine was removed by 

 spontaneous evaporation from the product, which was purified by pres- 

 sure between folds of filter paper and crystallization from carbonic 

 disulphide. By this method from 6.5 grms. chlorbromacrylic acid we 

 obtained 8.5 grms. essentially pure chlortribrompropionic acid, or about 

 seventy per cent of the theoretical amount. 



This acid is readily soluble in ether and alcohol, less soluble in cold 

 than in hot carbonic disulphide and chloroform. In contact with water 



* These Proceedings, Vol. XVI. p. 240. 



