MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



243 



and energy per day in the diet in both experiments were such as previous observation and experi- 

 ment with the same subject had indicated to be sufficient l>ut not excessive. Experiment No. 1<i 

 was as exact a duplicate as possible of experiment No. !». except that part of the fats and carbo- 

 hydrates of the ordinary diet of No. 9 were taken out and were replaced in No. 10 by an amount 

 of alcohol that was practically isodynamic with the fats and carbohydrates Cot- which it was sub- 

 stituted, as explained below. 



The preliminary digestion experiment preceding metabolism experiment No. 9 began with 

 breakfast January 6, L898, and continued 4 days. During this preliminary period the subject 

 was engaged in his usual occupation as laboratory janitor, save that he had as little muscular 

 exercise as practicable. His diet was essentially the same as during the period of actual experi- 

 ment in the calorimeter. 



The subject entered the respiration chamber on the evening of January 9, and experiment 

 No. 9 began at 7 a. m. on January 10 and continued until 7 a. m. January 14. During this 

 period within the chamber his occupation consisted of reading, writing, etc.. but with very little 

 muscular or mental activity. The diet furnished 120 grams of protein and 2,717 calories of 

 energy per day. 



Between the close of experiment No. !» and the beginning of No. 10 there was an interval of 

 about 4 weeks, in which the subject was engaged in his visual occupation as laboratory assistant. 

 The preliminary digestion period of No. 10 began with breakfast February 11, 1898, and continued 

 •4 days. The subject had as little muscular exercise as practicable aside from his regular 

 occupation. The diet during the preliminary period was practically the same as during the 

 experiment proper. 



The subject entered the respiration chamber in the evening of February 14, and the experi- 

 ment proper began at 7 a. m. February 15 and continued 4 days. The diet of the experiment, 

 which furnished 123 grams of protein and 2.709 calories of energy per day. differed from the 

 diet of experiment No. 9 in that about 37 grams of fat and 45 grams of carbohydrates, supplying 

 520 calories of energy, were taken out of the ordinary diet and were replaced by 80 grams of 

 commercial alcohol with 90.6 per cent or 72.5 grams of absolute alcohol, having a heat of combus- 

 tion of 512 calories. Thus, the amount of alcohol was very nearly isodynaniic with the amounts 

 of fats and carbohydrates which it replaced, and the total amounts of protein and energy were 

 practically the same in the diets of both experiments. 



The following table summarizes the results of these two experiments. Detailed data of the 

 experiments will be found in Bulletin 69 of the Office of Experiment Stations of the United States 

 Department of Agriculture. 



Table 2. — Summary of result* of metabolism experiments Nos. 9 and 10. 



[Quantities per day.] 



