350 PROCEEDINGS OF THE AMERICAN ACADEMY 



The solubility of the salt in water at 19°.5 was determined in the 

 usual manner. The calcium was preci^jitated as oxalate and ignited 

 with sulphuric acid. 



I. 6.5743 grm. solution saturated at 19°.5 gave 0.1522 grm. CaSO^. 

 11. 7.2115 grm. solution saturated at 19°.o gave 0.1689 grm. CaSO^. 



The solution saturated at 19°. 5 therefore contained the following 

 percentages of anhydrous salt: 



I. II. 



6.81 6.89 



Ethyl -^ Dichlorpyromucate, C.HCLOgCgH^. — The process by which 

 the ethyl ether was obtained has already been described. It is readily 

 soluble in hot alcohol, sparingly soluble in cold alcohol, and crystallizes 

 in clustered prisms with rectangular truncations which melt at 72-73°. 

 A sample of the ether melting at 72-73° was distilled under a pressure 

 of 16 mm. and boiled constant at 122°. 5, temperature of bath 170-175°. 

 For analysis the ether was dried over sulphuric acid. 



I. 0.2034 grm. substance gave 0.2790 grm. AgCl. 



II. 0.2302 grm. substance gave 0.3160 gfm. AgCl. 



Calculated for Found. 



CeHCloCOjHB. I. n. 



CI 33.98 33.91 33.94 



In order to determine the constitution of this dichlorpyromucic acid 

 we studied its oxidation products with aqueous bromine. 



Action of Bromine and Water. 



As it was desirable to compare the oxidation product obtained from 

 this acid with that obtained from the ^SS dichlorpyromucic acid under 

 the same conditions, the acid was suspended in five times its weight of 

 water, somewhat more than four atoms of bromine added as rapidly as 

 possible, and the solution boiled until the oil which was at first formed 

 had nearly disappeared. The filtered solution was evaporated to dry- 

 ness at a gentle heat, the crystalline residue dissolved in a little cold 

 water, filtered, and again evaporated nearly to dryness. The acid 

 which separated was readily soluble even in cold water, almost insolu- 

 ble in hot cliloroform or benzol. It was therefore pressed dry with 

 filter paper and carefully extracted with hot benzol. The acid as thus 

 prepared crystallized in microscopic crystals which melted at 188-189°, 

 and moreover gave on analysis the percentage of chlorine required by 

 monochlorfumaric acid.* 



* Kauder, loc. cit. 



