IOWA ACADEMY OF SCIENCES. 99 



water. It was purified by washing with water, dissolvino: 

 in weak ammonia and filtering to remove any traces of 

 the original mother substance, reprecipitating with hydro- 

 chloric acid and recrystallizing from dilute alcohol two or 

 three times. The yield in the first experiment was 24 per 

 cent of theory. Later experiments apparently yielded 

 better results, but the resulting quantity of acid was not 

 weighed. The pure acid melts at 182-3^ C. It is of a 

 light yellow color and has no taste. It is slightly soluble 

 in hot water, from which on cooling it crystallizes out in 

 tufts of radial needles. It is insoluble in petroleum 

 ether, sparingly soluble in sulphuric ether, but is very 

 soluble in warm alcohol and in dimethyl aniline, benzal- 

 dehyde, nitro benzene, toluene, glacial acetic acid and 

 glycerine. The acid was analyzed by determining the amount 

 of silver in the silver salt which yielded results as given 

 below. In the second analysis the silver salt had darkened 

 somewhat by being allowed to remain some time in con- 

 tact with a solution of silver nitrate during the process of 

 manufacture: 



Calculated for AgC^jH^NO. I. II. 



Ag. 30.09 30.09 30.59 



A portion of the acid was dissolved in dilute ammonium 

 hydroxide, the excess of ammonia evaporated off and 

 observations made as to the character of the precipitates 

 yielded by various metallic salts, with results as follows: 



Copper sulphate light greenish blue. 



Aluminum chloride white. 



Lead nitrate white floculent. 



Manganese chloride white. 



Cobalt chloride light pink. 



Magnesium sulphate white. 



Ferric chloride yellowish white. 



Ferrous sulphate light yellow. 



Cadmium chloride white crystalline. 



Mercuric chloride white. 



Platinum tetrachloride yellow. 



Nickel, calcium, strontium and barium salts yielded no 

 precipitate with the dilute solutions used. The solution 

 was very dilute, and in some cases would undoubtedly 

 have yielded a precipitate if it had been more concen- 



