l6 QUATERCENTENARY STUDIES IN PATHOLOGY 



Dog I (Table I.). As already pointed out, this dog developed a 

 marked nephritis, so that the urinary analysis was rendered extremely 

 difficult and possibly inaccurate towards the end of the investigation. 



Until proteid made its appearance in any considerable quantity the 

 relative amount of urea and ammonia were about the normal. The purin- 

 nitrogen excretion previous to the day on which meat extract was given 

 averaged about 0*04 gr., which is distinctly higher than the average for a 

 dog of this size. When meat extract was added to the otherwise purin- 

 free diet, a very distinct increase in purin excretion resulted.* 



After albuminuria developed, the relative amount of urea-nitrogen 

 steadily fell, more than 50% of the total nitrogen being excreted in the 

 form of proteid. The absolute amounts of urea and ammonia remained, 

 however, nearly unchanged. 



Urine of Dog j. — The results of this investigation are given in Table 

 II., from an examination of which it will be seen that the daily excretions 

 of nitrogen, ammonia and urea were very high and to a corresponding 

 degree, the nitrogen of ammonia being on an average about 7 per cent, 

 of the total nitrogen, and that urea about 79 per cent. The rapid 

 emaciation of this dog probably accounts for the high nitrogen content 

 of the urine. 



On March 15th a dose of 10 grams of ammonium acetate was given 

 by the stomach tube with the result that on the same day and the day 

 following a marked diuresis was induced, but with no increase of the 

 ammonia excretion on either day, whereas on the day following there 

 was a very marked increase in the excretion of urea, its nitrogen being 

 88 per cent, of the total nitrogen. On the 17th of March 5 grams of 

 ammonium carbonate (containing, therefore, carbamate) had likewise no 

 effect on the ammonia excretion, but raised very considerably that of 

 urea. 



Regarding the purin excretion, it will be seen that this was fairly 

 constant (viz., about 0*04 gms. purin-nitrogen), except on the 17th of 



* Burian and Schur (" Uber die Stellung der Purinkorper im menschlichen Stofwechsel," 

 Arch. f.d. ges. Physiologic, 1901. Bd. 87, p. 291.) have shown that in normal dogs about 5% 

 of ingested oxypurin (xanthin and hypoxanthin) reappear in the urine. Our object in giving 

 the meat extract in the above experiment was to see whether the same integral factor would 

 hold for a dog with Eck's fistula. The incidence of albuminuria, however, renders the 

 observed result too inaccurate to draw any conclusion. 



(280) 



