464 CHEMISTRY OF THE LEUGOMAim. 



duced the salts of silver and mercury. Its formula probably corres- 

 ponded to CjjHj^NjOg or CjHjjNjO^. A third alkaloid, parareducin, 

 formed a zinc compound having the composition CgHjNjO.ZnO. 

 A fourth base is said to give a compound with platinum chlorid and 

 to contain an aromatic nucleus (aromin). Besides 'these four bases 

 Thudichum described two other substances which he considered to 

 be basic. These were urochrome, the normal pigment of the urine, 

 and creatinin. 



In 1880, Pouchet announced the presence of carnin, CyHgN^Oji 

 Kriiger and Salomon did not meet with carnin in their exhaustive 

 study of the purin bases in urine and, moreover, they question the 

 correctness of Pouchet's finding. The latter also reported another 

 base which he subsequently analyzed and found to have either the 

 composition CjHjjN^Oj or CyHj^N^Oj. This substance formed de- 

 liquescent fusiform crystals, sometimes grouped in bundles or 

 irregular spheres. It possessed a slight alkaline reaction and 

 combined with acids to form crystallizable salts. It was soluble in 

 dilute alcohol, almost insoluble in strong alcohol, insoluble in ether. 

 The hydrochlorid yielded double salts with gold chlorid, platinum 

 chlorid, and mercuric chlorid. The platinochlorid formed deliques- 

 cent golden-yellow rhombic prisms. This base occurred in the 

 dialysate (see page 320). From the non-dialyzable portion, Pouchet 

 obtained another base corresponding to the formula CjHjNO^, which 

 he called the " extractive matter of urine." It gave precipitates 

 with the general alkaloidal reagents, was non-crystallizable, altered 

 on exposure to air and was resinified by hydrochloric acid. On 

 the addition of platinum chlorid it rapidly oxidized, but did not 

 yield a platinochlorid. The bases were poisonous to frogs ; produced 

 paralysis, loss of reflexes, and stoppage of the heart in systole. The 

 same author regarded the urine as containing very small quantities 

 of some pyridin bases, analogous to or identical with those obtained 

 by Gautier and Etard from decomposing fish. 



Baumstark isolated a compound from the urine having the compo- 

 sition CjHgNjO. In forty liters of urine it could just be detected ; 

 was more abundant in one case of icterus. It was not present in 

 dog's urine, except after feeding benzoic acid. It crystallized 

 from water in white prisms resembling hippuric acid. The crystals 

 decrepitate on heating ; are unchanged at 250°, but at higher temper- 

 ature give off dense, white vapors having a peculiar odor ; melt and 

 take fire. The odor is that of burned horn. It is rather easily 

 soluble in hot water, difficultly in cold water and in alcohol ; not in 

 absolute alcohol or ether. The solutions are neutral. It forms 

 easily soluble salts. The hydrochlorid, CjHgNjO.HCl, crystallizes 

 difficultly in dendritic masses ; is deliquescent and soluble in alcohol. 

 It does not combine with bases, and is precipitated by mercuric nitrate, 

 thus resembling allantoin and urea. When heated in a glass tube 



