192 MUCIC ACID. 



dulcite, gum Arabic, mucilage, sugar of milk, and 

 melitose, with nitric acid. "White, crystalline powder, 

 very slightly soluble in cold water, more easily in 

 boiling (in 50 parts), insoluble in alcohol. 



The neutral potassium salt, C 6 H 8 8 K 2 , crystallizes 

 readily, is almost insoluble in cold water, easily soluble 

 in hot water; the acid salt, C 6 H 8 8 HK, forms more 

 easily soluble crystals. The neutral ammonium salt, 

 6 H 8 8 (NH 4 ) 2 , crystallizes in prisms, difficultly soluble 

 in cold water. Is decomposed, by heating, into am- 

 monia, water, pyrrol (C 4 H 5 K, a colorless, liquid base, 

 boiling at 133), and other products. 



Ethyl mucate, C 4 H 4 (OH) 4 co.ac, is obtained 

 by heating mucic acid with sulphuric acid and 

 alcohol. 



Four-sided columns, easily soluble in boiling water 

 and boiling alcohol, but slightly in cold. Fuses at 

 158. When treated with "OTS'O.Cl, it yields ethyl 

 tetracetylmucate C 4 H 4 (O.C 2 H 3 0) 4 (CO.O.C 2 II 5 ) 2 . Colorless 

 needles of a vitreous lustre, but slightly soluble in 

 water, cold alcohol, and ether, easily soluble in hot 

 alcohol. Fuses at 177, and sublimes even at 150. 



Phosphorus chloride converts mucic acid into a 

 crystallizing chloride C 6 H 2 C1 2 2 C1 2 , which is decom- 

 posed by water into hydrochloric acid and chlormu- 

 conic add C 6 H 4 C1 2 4 . Crystals, which are difficultly 

 soluble in cold water, easily in boiling. Bibasic. 

 Treated with sodium-amalgam and water, it yields 

 muconic add C 6 H 8 4 . Prisms, sometimes an inch in 

 length, difficultly soluble in cold water, easily soluble 

 in hot water and alcohol. Bibasic acid. By con- 

 tinued action of hydrogen, adipic acid (p. 164) is 

 produced. 



Pyromucic acid, C 5 H 4 3 , is produced by the dry 

 distillation of mucic acid. The distillate is supersatu- 

 rated with sodium carbonate, filtered, and evaporated 

 down to a small volume ; and, after acidifying with 



