BORIC ACID UPON NUTRITION. 35 



tionable influence upon proteid metabolism. In this period of 

 eight days 64 grams of borax were administered, and under 

 its influence the excretion of nitrogen through the urine was 

 greatly increased. As in the other experiments, the propor- 

 tion of nitrogen in the faeces was likewise increased, implying 

 decreased assimilation of proteid food, but the nitrogen balance 

 of 4.878 is mainly due to direct stimulation of proteid 

 metabolism. When, however, it is considered that to accom- 

 plish this result a daily dose of 8 grams of borax was required, 

 and for eight consecutive days, with a dog weighing only 

 10 kilos, it is very plain that proteid metabolism is not readily 

 affected by borax. 



In the boric acid period of eight days, with a total dosage 

 of 17 grams of the acid, there is some evidence of diminished 

 proteid metabolism. The excretion of nitrogen through the 

 urine is certainly diminished ; there appears to be a sparing of 

 proteid, but it is to be noticed that, in the period following, 

 the nitrogen balance remains unaltered, which fact casts some 

 doubt upon the assumption that the result is due solely to 

 the acid. It is of course possible that the action of the boric 

 acid may be continued into the after period, but this we 

 should hardly expect in view of the rapid elimination of 

 boric acid from the system. Further, after the second borax 

 period, where the nitrogen balance is so noticeably disturbed, 

 there is a quick return to the normal, the nitrogen balance for 

 the final period dropping back to 0.661. Consequently, 

 while the analytical data show a retention of nitrogen dur- 

 ing the boric acid period, thus indicating diminished proteid 

 metabolism, we feel some hesitation in attributing the result 

 wholly to the boric acid, particularly as the earlier experiment 

 with boric acid gave essentially negative results. 



Especially noticeable in this experiment, as in the earlier 

 experiment with borax, is the action of the latter agent in 

 reducing the volume of the urine. (See table showing general 

 summary.) In both borax periods the total volume of urine 

 excreted is distinctly reduced, and the same holds true in this 

 experiment with the boric acid. It is quite probable that the 



