BORIC ACID AND BORAX. 215 



noticeable in the first preservative subperiod. The second subperiod 

 shows a slightly decreased nitrogen excretion. In the fourth subperiod 

 there is again a decrease in the amount of nitrogen excreted. During 

 the after period there is an increase in the amount of nitrogen excreted, 

 the balance being restored almost to the normal of the fore period, 

 namely, to 0.83. 



A comparison of Nos. 7, 8, 9, 10, and 12 may also be given for the 

 fore period and the first preservative subperiod of one-half gram per 

 day. After that period No. 7 was ill and dropped out altogether, and 

 Nos. 11 and 12 received special treatment. 



For the fore period the daily nitrogen balance of Nos. 7, 8, 9, 10, 

 and 12 is 1.03, and during the first preservative subperiod, one-half 

 gram daily, 0.97, showing a slight increase in the percentage of nitro- 

 gen excreted. 



Nos. 11 and 12 may also be compared for their special treatment, in 

 which for the fore period the daily average balance for Nos. 1 1 and 12 

 is 0.13, and during the preservative period the average daily balance 

 is 0.75, showing a slightly decreased excretion of nitrogen. The 

 nitrogen in these cases seems to be retained for the purpose of 

 restoring the tissues broken down by previous ill health. 



For the after period the average daily balance is 0.91. 



Only three out of the six members of this table completed the entire 

 period of experiment, Nos. 2 and 6 having suffered during a part of 

 the time from illness and No. 4 having withdrawn from the table 

 May 25. 



The experience of the previous series having shown that the admin- 

 istration of increasing doses of borax produced feelings of distress, 

 both in the stomach and in the head, it was determined during this 

 series to give a minimum quantity, namely, one-half gram per day, and 

 the period of experiment was extended to cover a little over two 

 months, namely, from April 24 to June 29. 



For purposes of comparison this period was subdivided into several 

 periods, namely, the fore period of April 24 to May 1, the preserva- 

 tive period of four subperiods from May 2 to June 20, inclusive, and the 

 after period from June 21 to 29, inclusive. The average daily balance 

 of the fore period is 0.60; of the first preservative subperiod, 1.26; of 

 the second, 0.93; of th third, 0.33; of the fourth, 0.52, and of the 

 after period, 1.08. 



It is seen that there was but very little effect produced as a whole 

 upon the nitrogen excretion during these periods. The individual 

 variations, however, are somewhat marked, thus giving additional 

 evidence of the danger of basing conclusions upon too few observations. 



