PROTEIN METABOLISM 93 



different for different individuals, but wholly inde- 

 pendent of quantitative changes in the total amount of 

 nitrogen eliminated. 



2. Uric Acid. When the total amount of protein 

 metabolism is greatly reduced, the absolute quantity of 

 uric acid is diminished, but not nearly in proportion to 

 the diminution in the total nitrogen, and the per cent 

 of the uric acid nitrogen in terms of the total is, there- 

 fore, much increased. 



3. Ammonia. With pronounced diminution in the 

 protein metabolism (as shown by the total nitrogen in 

 the urine), there is usually, but not always, and there- 

 fore not necessarily, a decrease in the absolute quan- 

 tity of ammonia eliminated. A pronounced reduction 

 of the total nitrogen is, however, always accompanied 

 by a relative increase in the ammonia-nitrogen, pro- 

 vided that the food is not such as to yield an alkaline 

 ash. 



4. Urea. With every decided diminution in the 

 quantity of total nitrogen eliminated, there is a pro- 

 nounced reduction in the per cent of that nitrogen 

 represented by urea. When the daily total nitrogen 

 elimination has been reduced to 3 gm. or 4 gm. about 

 60 per cent of it only is in the form of urea. 



5. Inorganic Sulphates. Decided diminutions in 

 the daily elimination of total sulphur are accompanied 

 by reductions in the per cent of the sulphur present as 

 inorganic sulphates. The reductions are as great as in 

 the case of urea. 



6. Neutral Sulphur. The neutral sulphur elimina- 



