ITAMONOCHLORPYROTARTARIC ACID, ETC. 163 



according to the acid from which they are produced, 

 by means of the prefixes ita, citra, and mesa. 



Ita-, Citra-, and Mesamonochlorpyrotartaric 

 acids,C 5 H 7 C10 4 , are produced by heating the three acids 

 with strong hydrochloric acid. They all cyrstallize. 

 The ita-acid melts at 140-145. When heated with 

 water or bases, it is transformed into itamalic acid. 

 The citra-acid is very unstable, breaks up, in a dry con- 

 dition, as well as in solution, by gentle heating, into 

 hydrochloric acid and mesaconic acid ; by heating with 

 bases, into hydrochloric acid, carbonic anhydride, and 

 crotonic acid (p. 123). The mesa-acid is more stable; 

 fuses without decomposition at 129-130; yields, how- 

 ever, the same products as the citra-acid, by boiling 

 with water. 



Ita-, Citra-, and Mesadibrompyrotartaric 

 Acids, CMl'Bi^O 4 , are crystalline, of different solubility 

 in water; the citra-acid most easily soluble, the ita-acid 

 most difficultly. When a solution of its sodium salt 

 is heated, the ita-acid yields easily soluble, crystalline 

 (jwu'c acid C 5 II 4 4 ;the citra- and mesa-acids, on the 

 other hand, yield bromcrotonic acid (p. 123) under like 

 circumstances. 



treated with sodium-amalgam, all the substi- 

 tution-products yield the same pyrotartaric acid. 



Amidopyrotartaric acid (Glutamic acid), C 5 IP 

 4 = C 3 I L 5 .N11 2 (CO.OII) 2 . Is contained, together with 

 amidoaucdnic acid, in beet-molasses; and is formed, 

 together with the same acid, by boiling albuminous 

 substances with dilute sulphuric acid. Colorless, 

 rhombic octahedral crystals ; fusing point, 135-140 ; 

 difficultly soluble in cold water ; almost insoluble in 

 alcohol. * 



The succeeding acids of this series are formed simul- 

 taneously by the action of nitric acid on fats and fatty 



