350 The Philippine Journal of Science i9i8 



the proportion of urea nitrogen falls to about 60 per cent of 

 the total nitrogen. Mathews' (8) explanation of this variation 

 of urea with the diet is that — 



When more protein is eaten than is necessary to replace that decomposed 

 in the vital process in the body, the body does not restore the excess 

 since there is no provision for the storage of an excess of protein except 

 in relatively small quantities. Instead of storing the excess the nitrogen 

 is split off from the amino-acids converted into urea and excreted, while 

 the carbonaceous part of the amino-acid molecule is converted into glucose 

 or fat and stored in that form. 



Uric acid — Uric acid was determined in all cases by the Folin- 

 Shaffer method. (9) The excretion of uric acid in a diet free 

 from nucleo-proteins is fairly constant for each individual; it 

 is then a product of endogenous metabolism. It can be increased 

 by taking large amounts of animal food rich in nucleo-proteins, 

 such as thymus gland, fish roe, etc. Healthy Europeans excrete 

 from 0.30 to 0.75 gram of uric acid daily. In Americans it 

 varies from 0.30 to 1.2 grams, with an average of 0,75 gram. 

 The increased uric acid catabolism during fever, or in any con- 

 dition when there is increased cellular destruction, has been 

 observed by several investigators. (10) The average total output 

 of the Filipino series of 214 determinations is 0.376 gram per 

 day. The average of 61 observations among the students was 

 0.441 gram per day, and the series of 153 observations on the 

 prisoners, laboratory helpers, and hospital servants, gave an 

 average of 0.311 per day. This is very much lower than the 

 European or American standards. 



Creatinine. — Creatinine was determined in all cases by the 

 Folin colorometric method, (ll) using purified picric acid, as 

 suggested by Folin and Doisy.(l2) This is another product of 

 endogenous metabolism. Folin has shown conclusively that the 

 quantity of creatinine excreted on a low protein diet is prac- 

 tically the same as when the diet is rich in nitrogen. This con- 

 stancy of the excretion of creatinine indicates that it is an index 

 of the real metabolism of the vital machinery of the body proper 

 in distinction from catabolism which increases the free energy. 

 According to Folin the average excretion of creatinine in the 

 normal individual varies from 1 to 2 grams a day in tempe- 

 rate climates. The average creatinine output in the whole Fi- 

 lipino series of 235 determinations was 1.478 grams per day. 

 The average of 163 determinations on prisoners, laboratory 

 helpers, and hospital servants is 1.274. 



Leathes(i3) found that during fever the amount of creatinine 



