Increasing Quantities of Fat in Diet on Metabolism in Dogs. 295 



The Influence of Diet on the Total Alkaline and Aromatic Sulphates in 

 Normal Dogs and in those in which the Large Intestine has been in part or 

 completely Removed. 



Having discussed the faeces, we now come to consider the sulphates 

 in the urine. As we all know, the sulphur taken in the diet is princi- 

 pally excreted in the form of sulphates, either combined with alkalis 

 or with aromatic substances, although some 14 to 25 per cent, of the 

 total sulphur in the urine is excreted as neutral sulphides.* 



In this paper the sulphides were not determined. The sulphates- 

 contained in the urine are principally derived from the proteids in the 

 diet, as only very small quantities are taken in the form of salts, and, 

 in consequence, the ratio of sulphuric acid to nitrogen excreted in the 

 urine remains very parallel 5 : 1. Hence it will be seen in the 

 following tables that the proteid-sparing action of the increase of fat 

 causes not only a decrease in the nitrogen in the urine in normal dogs 

 but also a decrease in the quantity of the sulphates. The sulphur of 

 the proteids in fact had been retained in the organism for building up 

 the proteid of the body itself, in the same way as the nitrogen had 

 been. 



The aromatic sulphates were also investigated after removal of the 

 large intestine in order to see if the intestinal putrefaction was in any 

 way influenced by the removal of the large intestine ; for the experi- 

 ments of Salkowski,t Baumann,:}: &c., have shown that in all prob- 

 ability the phenol, indol, &c., which, when absorbed into the blood, go 

 to form the aromatic sulphates, are only formed in the large intestine. 



Baumann and Ewald have described cases of intestinal fistula ; 

 during the time in which the faeces were excreted through the fistula 

 the quantity of aromatic sulphates was very much diminished in the 

 urine. 



Table XXI. In normal dogs the analyses of the sulphates were 

 carried out during three periods in which the dog received progres- 

 sively an increase of fat in his diet. 



We have already seen that this increase of fat caused a decrease in 

 the quantity of urine and in the quantity of nitrogen daily eliminated. 

 Accompanying this, we find in the above table there is also a decrease 

 in the quantity of the alkaline sulphates progressively with the increase 

 of fat. On the other hand, the aromatic sulphates are not influenced 

 by the increase of fat to 32'04 grams per diem; but on increasing the 

 fat to 62-04 grams there is an apparent decrease in the aromatic 

 sulphates. 



* v. Noorden, ' Lehrb. d. Path. Stoff., 1 p. 283. 



f Salkowski, 'Zeit. f. Phys. Chemie,' vol. 10, p. 266, 188G. 



J Baumann, ibid., vol. 10, p. 126, 1886. 



Ewald, ' Arch, f . Path. Anat.,' vol. 75, p. 409. 



