APPENDIX. 

 TABLES SHOWING BALANCES OF FOOD ELEMENTS. 



EXPLANATION. 



The sheets on which the balances of nitrogen, phosphoric acid, fat, calories, and 

 solids were calculated are printed in full. The nitrogen sheets, for example, include 

 the number of grams of nitrogen per day in the food consumed and the number of 

 grams eliminated in the feces and in the urine, the figures being taken from sheets 

 on which they have been previously calculated from the weights and the percentage 

 composition. From these figures data are calculated for the succeeding columns, 

 which show the percentages of nitrogen eliminated in the feces, in the urine, and 

 in both, and also the balance between the quantity of nitrogen ingested and the 

 quantity excreted. For the convenience of calculators the columns are numbered 

 at the top, and just below the heading the necessary calculation is indicated in 

 parentheses. For instance, column 4 is calculated by adding together the corre- 

 sponding figures of columns 2 and 3; column 5 by dividing the figures in column 2 

 by those in column 1; while the balances in column 8 are obtained by subtracting 

 the results in column 4 from those in column 1. Exceptions to the general method 

 of calculation are the total and the average in column 4, which are not obtained 

 by adding together the totals and averages respectively in columns 2 and 3. The 

 total in column 4 is obtained by adding together the various individual figures in 

 the same column, and the average by dividing the total by the corresponding num- 

 ber of days. The sheets for phosphoric acid, fat, calories, and solids are similarly 

 arranged. 



For various reasons it sometimes happened that a sample of urine or feces of an 

 individual for a single day was lost. This was sometimes occasioned by the break- 

 age of a receptacle, sometimes by sickness of a member of the table, sometimes by 

 accident in the analytical work. As the work progressed and was better systema- 

 tized these losses of samples became less frequent. 



In order to secure all possible data the analysis of the food and feces is given, even 

 for those days for which the sample of urine was lost, and the analysis of food and 

 urine for those days on which the sample of feces was lost. In the first case, how- 

 ever, the amount of nitrogen, phosphoric acid, fat, calories of combustion, or 

 solids of the food and of the feces is placed in brackets. In the second case, in 

 which the sample of feces was lost, the grams of nitrogen, etc., in the food and in the 

 urine are placed in parentheses. The figures given without either brackets or paren- 

 theses therefore represent those days for which the analysis of food, feces, and urine 

 was complete. 



In the totals of each period and subperiod it was desired to have as full informa- 

 tion as possible. In determining the amount of nitrogen, etc., eliminated in both 

 feces and urine of course only those figures could be employed which were not 

 inclosed in either brackets or parentheses; that is, for those days for which both 

 feces and urine were entirely saved and examined. For the total amount of nitrogen, 

 etc., in the feces alone for a given period or subperiod, however, not only are the 

 uninclosed figures added together, but also those inclosed in brackets are included, 

 and for comparison with them the amount of nitrogen, etc., in food for the same 

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