BORIC ACID AND BORAX. 257 



days is determined; that is, the figures in the first column which are neither in 

 brackets nor in parentheses are added to the figures in brackets. In order to deter- 

 mine the total nitrogen eliminated in the urine the figures for those days for which 

 both the feces and urine were all saved and examined are added to those in which the 

 urine was saved but the feces lost; that is, the figures which are neither in brackets 

 nor parentheses are added to the figures in parentheses. For comparison with them 

 the amount of nitrogen, etc., in food for the corresponding days was also deter- 

 mined; that is, the figures in column 1 which are neither in brackets nor in paren- 

 theses are added to the figures in parentheses. 



In Table XLV, for instance (subject No. 1, Series I), the number of grams of nitro- 

 gen in the food for the fore period (December 16-21, 1902), was 113.226. This 

 figure includes the nitrogen in the food for December 16, when the sample of urine 

 was lost. The nitrogen in the food for December 16 is therefore inclosed in 

 brackets, and the sum of the nitrogen for all the days on which the feces were 

 saved, in this case for all days of the period, is also inclosed in brackets. The same 

 is true of column 2, in which the nitrogen of the feces is given. The urine and feces 

 were both saved for all days of the period excepting December 16, and the sum of 

 the nitrogen in the food for those days is given, and the result expressed in figures 

 that are not inclosed in either brackets or parentheses. 



The average amount of nitrogen, etc. , in the food for each day on which both feces 

 and urine were analyzed is determined by dividing the number which is not in 

 parentheses, 94.948, by the number of days represented in this sum; that is, from 

 December 17 to December 21, inclusive. The figure so obtained represents the aver- 

 age amount of nitrogen for one day of the period when both urine and feces were 

 examined and is not placed in either brackets or parentheses. The average amount 

 of nitrogen in the urine is of course obtained by dividing the total number of grams 

 for the period by the same number of days. 



On the other hand, the average number of grams of nitrogen in the food for each 

 day on which the feces were collected and examined is obtained by dividing the sum 

 in brackets, 113.226, by the total number of days on which the feces were saved, that 

 is, from December 16 to December 21, inclusive, and the result so obtained is placed 

 in brackets. The average number of grams per day of nitrogen in the feces is also 

 obtained by dividing the number in brackets in the second column, 8.735, by the 

 total number of days on which the feces were obtained; that is, from December 16 to 

 December 21, inclusive. 



The amount of nitrogen eliminated in both feces and urine is obtained, as directed 

 in the table, by adding together the amount eliminated each day in the feces to 

 the amount eliminated in the urine. To obtain this result the figures inclosed in 

 parentheses and brackets are omitted. The amount eliminated in both feces and 

 urine for a period or subperiod is determined by adding together the amount elim- 

 inated in both feces and urine for all individual days in that period or subperiod. 

 This figure of course does not include any of the figures expressed in brackets and 

 parentheses in columns 2 and 3. It is therefore not equal to the sum which includes 

 those results; for instance, in the table referred to above (Table XLV) the total 

 nitrogen eliminated in both feces and urine during the fore period refers only to the 

 time from December 17 to December 21, inclusive, and is not equal to the sum of 

 the amount of nitrogen eliminated in the feces (8.735 grams, which includes also 

 the data for December 16) and*the amount of the nitrogen in the urine for Decem- 

 ber 17 to 21 (76.880 grams) . This applies also to the other case mentioned; that is, 

 where the sample of feces is lost and the results on food and urine for the corre- 

 sponding days are inclosed in parentheses. 



The averages that would have been obtained by excluding all results for those days 

 on which either feces or urine were lost would not have differed greatly from those 

 4242 No. 84, pt 104 17 



