236 DERIVATIVES OF URIC ACID. 



iodide, and dimethylparabanic add (cholestrophane), 

 C 3 (CH 3 ) 2 N 2 3 , a compound, crystallizing in broad la- 

 minse, of a silvery lustre, easily fusible and sublimable. 

 Parabanic acid is decomposed when boiled with 

 dilute acids, yielding urea and oxalic acid. Nascent 

 hydrogen (zinc and hydrochloric acid) converts it into 

 oxalantine. 



Oxaluric acid, C 3 HW0 4 = CO j 



Bears the same relation to parabanic acid that alloxanic 

 acid bears to alloxan. The real salts of parabanic 

 acid do not appear to be capable of existence. Strong 

 bases immediately cause an assimilation of the elements 

 of water, with which parabanic acid is transformed 

 into oxaluric acid. The ethyl ether is produced by. 

 the action of ethyloxy-oxalyl chloride (p. 155) on urea. 

 When parabanic acid is dissolved in ammonia and 

 heated, the solution turns into a white mass of fine 

 crystals of a silky lustre. These are ammonium oxa- 

 lurate, C 3 H 3 N 2 4 .NH 4 . This salt is also contained in 

 small quantity in urine. It is difficultly soluble in 

 water. When its solution in hot water is mixed with 

 an acid, oxaluric acid separates as a white crystalline 

 powder. It is very difficultly soluble, though the solu- 

 tion tastes and reacts acid. Its silver salt, C 3 II 3 N 2 4 Ag, 

 formed by double decomposition from the ammonium 

 salt, separates in thick, white nocks. It is soluble in 

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

 fine needles of a silky lustre. When a solution of 

 oxaluric acid is heated for some time to boiling, it is 

 converted into urea oxalate and oxalic acid. 



{NTT 2 

 mr 

 * L ' 



XX"* 1 is formed, as a white precipitate, when a 



solution of alloxan is mixed with hydrocyanic acid 

 and then with ammonia. Alloxan is thus resolved 

 into oxaluramide, dialuric acid, and carbonic anhy- 

 dride water and ammonia being assimilated. White, 

 crystalline powder, but slightly soluble in water; 



