OF ARTS AND SCIENCES. 831 



The acid obtained by acidification melted at 145-146°, contained the 

 percentage of chlorine required by a chlorpyromucic acid, and appeared 

 to be in all respects identical with the acid obtained from the /38 dichlor- 

 pyromucic acid. While the yield of pure acid was in this case but 

 50 per cent of the theoretical amount, it is possible that it might be 

 somewhat increased by further experiments. From the third iso- 

 meric dichlorpyromucic acid, subsequently described, we have as yet 

 been able to obtain no definite reduction product. 



The {3 chlorpyromucic acid dried over sulphuric acid gave on analy- 

 sis the following results : — 



I. 0.2710 grm. substance gave 0.4073 grm. C0 2 and 0.0513 grm. H 2 0. 

 II. 0.1385 grm. substance gave 0.1355 grm. AgCl. 

 III. 0.1736 grm. substance gave 0.1692 grm. AgCl. 



i. 



in. 



24.10 



Analysis III. was made with material prepared from the fiy dichlor- 

 pyromucic acid. 



/3 chlorpyromucic acid is readily soluble in hot water, sparingly sol- 

 uble in cold water, and crystallizes from hot aqueous solution in thin 

 irregular striated plates or flattened prisms. It is readily soluble in 

 alcohol, ether, hot benzol or hot chloroform, and is but sparingly sol- 

 uble in cold benzol or cold chloroform. "When repeatedly crystallized 

 from hot water it melted at 145-146°, and recrystallization from other 

 solvents failed to raise this melting point. 



In order to determine the solubility of the acid in cold water, a 

 weighed quantity of a solution of the acid saturated at 19°.8 was boiled 

 with baric carbonate, and the barium taken into solution precipitated 

 as sulphate. 



I. 31.6300 grm. solution saturated at 19°.8 gave 0.201 9 grm. BaS0 4 . 

 II. 34.0328 grm. solution saturated at 19.°8 gave 0.2176 grm. BaS0 4 . 



The solution saturated at 19°.8 therefore contained the following 



percentages of the acid : — 



i. n. 



0.80 0.80 



For the further characterization of the acid we prepared certain of 

 its salts. 



