SUCCINIC ACIDS. 159 



PbO,H 2 0. White insoluble precipitate. Silver mesox- 

 alate C 3 5 Ag 2 + H 2 0. Colorless, amorphous precipitate, 

 which is rapidly transformed into yellowish colored 

 crystals. Becomes discolored quickly in the air, and is 

 decomposed by boiling with water into carbonic anhy- 

 dride, silver oxalate, metallic silver, and free mesoxalic 

 acid. 



3. Succinic Acids. 



There are two differently constituted acids of this 

 composition possible. Both are known. 



1. Succinic acid (Ethylene succinic acid), 



cmco.oii 



OH 2 CO OH contained in amber, in some bituminous 



coals, in a number of plants, in the animal organism, 

 and also in urine. Is produced by continued action of 

 nitric acid on fats, and a great many other bodies ; by 

 fermentation of crude calcium malate; and, in small 

 quantity, by the fermentation of sugar; from malic 

 and tartaric acids by means of hydriodic acid ; from 

 ethylene cyanide and /3-cyanpropionic acid by heating 

 with alkalies. 



It is prepared by the dry distillation of amber. The 

 acid that passes over is purified by pressing and recrys- 

 tallization. Most readily by fermentation of crude 

 calcium malate with water and old cheese at 30-40. 

 The calcium succinate, formed in the course of several 

 days, is decomposed by means of sulphuric acid, filtered, 

 evaporated, and the acid purified by means of crystal- 

 lization. Clear crystals, fusing at 180 and boiling at 

 235, being decomposed at this temperature into water 

 and succinic anhydride. Soluble in 23 parts of cold 

 water, more easily in hot, less in alcohol. In the pre- 

 sence of a salt of uranium in sunlight it breaks up, in 

 aqueous solution, into carbonic anhydride and propionic 

 acid. 



The salts of the alkalies are easily soluble in water ; 

 the calcium salt C 4 H 4 O^Ca is difficultly soluble, separates 



