696 URINE. 



ether but soluble in amyl alcohol. On distillation with zinc-dust the 

 red pigment gives a strong odor of skatol. 



Urines containing skatoxyl are colored dark red to violet by JAFFE'S 

 indican test even on the addition of hydrochloric acid alone; with nitric 

 acid they are colored cherry red, and red on warming with ferric chloride 

 and hydrochloric acid. A red coloration of the urine can also be brought 

 about by the appearance of indigo red (indirubin) and a confusion of 

 this pigment can also take place. ROSIN 1 is of the opinion that no 

 skatol chromogen exists in human urine, and that the observations made 

 heretofore were due to a confusion of skatol red with indigo red or urorosein. 

 It cannot be disputed that derivatives of skatol sometimes occur in 

 human urine, and to prevent confusion with indigo red it must be borne 

 in mind that indigo red is soluble in chloroform as well as in ether, while 

 skatol red is inso^ble in these solvents. On the contrary skatol red is 

 soluble in amyl alcohol, and this solution shows absorption bands close 

 to the line D between it and E, corresponding to >} = 577-550 (PORCHER 

 and HERviEUx 2 ). 



In regard to a confusion of skatol red for urorosein it must also be 

 remarked that urorosein may also be a skatol red. The chromogen of 

 urorosein, as HERTER has shown in a case, is identical with indol acetic 

 acid, which passes into skatol on splitting off carbon dioxide. Accord- 

 ing to HERTER 3 urorosein is not identical with skatol red, although the 

 investigations of STAAL, GROSSER, PORCHER and HERVIEUX 4 indicate 

 that they are identical, and the last two investigators consider them 

 identical, because they both have the same spectrum and the same 

 chemical behavior. 



C.CH 2 COOH 

 Indol Acetic Acid (skatol carboxylic acid), C 10 H 9 N0 2 , C 6 H 4 <^ScH 



NH 



This acid, whose occurrence in the urine was first shown by SALKOWSKI, is found 

 in the urine in special putrefactive processes in the intestine (HERTER) and in 

 various diseases, especially 'in cachectic conditions. This* is of course dependent 

 upon the fact whether indol acetic acid is the actual chromogen of urorosein, and 

 also whether the experience obtained as to the occurrence of urorosein can be 

 applied to the indol acetic acid. According to WECHSELMANN 5 it occurs (more 

 correctly as urorosein) as traces in normal urine, abundantly in horse urine, 



and in especially large quantities in cow urine. When introduced into, the animal 

 body it appears unchanged in tl 



the urine. 



1 Rosin, Virchow's Arch., 123. 



2 Zeitschr. f. physiol. Chem., 45. 



3 Journ. of biol. Chem., 4. 



4 Staal, Zeitschr. f. physiol. Chem., 46; Grosser, ibid., 44; Porcher and Hervieux, 

 ibid., 45; Compt. rend., 138, and Journ. de Physiol., 7. 



5 Salkowski, Zeitschr. f. physiol. Chem., 9; Wechselmann, cited in Bioch. Centralbl., 

 5, 784. 



