. SULPHUR 179 



of the urine is related to the creatine of muscle, and that 

 the latter is connected with the nutritional condition and 

 not with the activity of muscular tissue. 



As regards the seat of formation of creatinine, the 

 diminution in this substance found in most hepatic diseases 

 points to its occurring in the hver. On the other hand, 

 creatinine continues to be excreted after the establishment 

 of an Eck fistula. 



Concerning the substances from which creatine is formed 

 we have no definite knowledge. 



It will be seen that the significance of creatine and 

 creatinine is far from clear. It is impossible in the present 

 state of knowledge to state what part these substances 

 play in metabolism. 



5.— METABOLISM OF SULPHUR 



Sulphur is taken into the body principally as cystine — 

 CH2- — S — S — CII2 



I I 

 CHNH2 CHNH2 



COOH COOH 



a constituent of most food proteins. 



Sulphur is excreted in the urine in three forms : — 



1. Inorganic sulphates. 



2. The so-called "neutral sulphur "—an incompletely 

 oxidised form the exact composition of which is unknown. 



3. Ethereal sulphates. 



It is also excreted in the bile as taurine, which enters 

 into the formation of one of the bjle-salts — sodium tauro- 

 cholate. 



Inorganic sulphates resemble urea in their relation to 

 diet. After a protein meal the excretion of inorganic 

 sulphates and of urea rise and fall almost simultaneously. 

 It is therefore concluded that these sulphates, like urea, 



