THE AROMATIC OXY-ACIDS. 287 



so-called neutral sulphur. Normally this constitutes about 1 2-1 5 

 per cent, of the total amount. 



The neutral sulphur bodies which have been described in the urine 

 of man under normal conditions are certain sulphocyanides, the so- 

 called oxyprotei'nic acid, alloxyprotei'nic acid, and antoxyprotei'nic 

 acid of Bondzynski and Gottlieb and Panek respectively, the uro- 

 proteic acid of Cloetta, and the uroferric acid of Thiel. The sul- 

 phocyanides in question are probably derived from the saliva and 

 the gastric juice, where they are normally found in traces. Oxy- 

 protei'nic acid contains 1.12 per cent, of sulphur, the alloxy com- 

 pound 2.19 per cent, and the antoxy acid 0.61 per cent. The uro- 

 ferric acid, according to Thiele, contains 3.46 per cent, of sulphur, 

 of which about one-half can be split off on prolonged boiling with 

 hydrochloric acid or sulphuric acid. In this respect, therefore, it 

 shows the behavior of a conjugate sulphate. In addition, however, it 

 contains sulphur, which cannot be split off even on prolonged boiling 

 with an alkaline solution of acetate of lead. Its amount is quite small. 



In the urine of cats, and less constantly of dogs, traces of thio- 

 sulphates are found, while in man they are normally absent. They 

 have been once found in a case of typhoid fever. Cystem and 

 ethyl sulphide are constant constituents of the urine of dogs. 



Whether or not taurocarbaminic acid is constantly present in 

 human urine has not been ascertained. I have shown, however, 

 that to a certain extent at least taurin is eliminated in this form 

 when given by the mouth. In cases of obstructive jaundice, more- 

 over, or after ligation of the common duct in dogs, the neutral 

 sulphur may increase to 40 per cent, of the total amount, and it is 

 known that in such cases taurocarbaminic acid is constantly present. 

 Its formation may be represented by the equation : 



/NH, 



C0< - C0 



\NH 2 \NH.C 2 H 4 .S0 2 .O.NH 4 . 



Taurin. Urea. Ammonium taurocarbamate. 



In all probability this synthesis is effected in the kidneys. In 

 rabbits, on the" other hand, taurin is largely oxidized to sulphuric 

 acid, while a small portion appears as thiosulphuric acid. 



Cystein. On feeding dogs with halogen benzols, peculiar products 

 appear in the urine, which contain both sulphur and nitrogen, and 

 which are apparently united with glucuronic acid. Baumann and 

 Preusse have termed these mercapturic acids. Following the ad- 



according to the equation : 



H 2 = CH 3 .COOH + C 9 H 10 BrNSO 2 



