BORIC ACID UPON NUTRITION. 11 



the conditions were therefore well adapted for bringing out 

 distinctly any possible influence the borax might have upon 

 the metabolic phenomena of the body. Further, we would 

 call attention to the obvious advantage in spite of the 

 greater labor involved of continuing experiments of this 

 character over comparatively long periods of time. To be 

 sure, in some cases where the substance being tested has a 

 marked physiological action, a single dose may show at once 

 the character of the influence exerted, but too often erroneous 

 conclusions are arrived at through negligence of this precau- 

 tion. Where, however, the substance under examination is 

 given for five to ten days consecutively, with careful ex- 

 amination of the excreta, the chances of detecting minor 

 influences are greatly increased, and at the same time the 

 danger of being led astray by a single exceptional result 

 or by other possible errors is greatly diminished. 



The tables on the three following pages contain the analyt- 

 ical results obtained throughout the experiment. 



On referring to the tables containing the results of the 

 first experiment, it is to be noted that hi the fore period of 

 nine days the total nitrogen ingested amounted to 88.326 

 grams, while in the urine excreted during this period there 

 were contained 87.185 grams of nitrogen, and in the faeces 

 2.122 grams, making a total of 89.307 grams of nitrogen; 

 hence the nitrogen balance for the period of nine days is 

 0.981 gram. The body-weight remained practically constant. 

 The slight excess of nitrogen excreted over the amount in- 

 gested in this period is due possibly to lack of complete 

 involution of the mammary glands ; * the deficiency, however, 

 is too slight, considering the length of the period, to need 

 much consideration. For comparison, the results of the 

 three periods showing the relative excretion of nitrogen, may 

 be arranged in tabular form (see p. 15). 



* MARCUSE : TJeber den Nahrwerth des Caseins, Pfliiger's Archly f . d. ges. 

 Physiol., 1896, Band 64, p. 223. 



