37 



formity of the diet, the regularity of tlie men in stooling, and the 

 long duration of the experiment, it is believed that no serious error 

 was thus introduced. The close agreement of the experiments also 

 confirms the belief. 



It was impracticable to collect the urine voided in these experi- 

 ments, and therefore the balance of income and outgo of nitrogen 

 was not ascertained. 



COMPOSITION OF FOOD MATERIALS AND FECES. 



All of the food materials were sampled at the time of use. Usuallj^ 

 the same kind of food was used at several meals, and in such cases 

 a composite sample was made for analj^sis. The samples were kept 

 frozen in suitable jars and brought to the laboratory- of the Maine 

 Experiment Station, where they were dried, subsamj)led, and ana- 

 lyzed by the usual methods. The feces were deposited in large 

 museum jars, and kept frozen until brought to the station for analy- 

 sis. The heats of combustion of all of the foods and of the feces 

 were determined by the usual method with the bomb calorimeter. 

 The results of the analyses of the foods are included in Table 16 and 

 of the feces in Table 17. lu the case of the feces the analyses are 

 reported on a water-free basis, as the amount of water in feces is not 

 imiiortant in computing the results of digestion experiments. 



Table 16. — Comjiosition of food materkds in, digestion experiments tvith Maine 



lumbcrnien. 



