46 REPORT OF OFFICE OF EXPERIMENT STATIONS. 



obtained as to the amount of the food material consumed which is 

 made available for use in the human body. 



The cooking experiments have been made with meat, and have 

 included the study of the effects of different methods of cooking upon 

 the meat with reference to composition, digestibilit}% nutritive value, 

 and pecuniary economy. 



The metabolism experiments have been conducted with the aid of 

 the respiration calorimeter. In these experiments the income and 

 outgo of the body were carefully observed under different conditions 

 of rest and work. The questions especially considered this year were 

 (1) the relation between muscular work and the metabolism of nitrogen, 

 and (2) the relative efficiency of fats and carbohydrates in the diet for 

 severe muscular work. The results obtained have been unusually 

 interesting and valuable. 



All these experiments include a large amount of analytical work, as 

 well as the determination of a considerable number of heats of com- 

 bustion by means of the bomb calorimeter. 



Considerable editorial work is also required to put the results of the 

 investigations in form for publication as either technical or popular 

 bulletins. The amount of editorial work has been somewhat larger 

 this year than usual. 



The nutrition investigations were carried on in cooperation with 

 colleges and experiment stations in Connecticut, Massachusetts, Maine, 

 New York, Tennessee, Illinois, Minnesota, and California. 



Five technical bulletins, two^farmers' bulletins, a yearbook article, 

 and two circulars on subjects relating to the food and nutrition of man 

 were issued during the past year's as follows: 



Bulletin 8^, pp. 39. — Nutrition Investigations at the California 

 Agricultural Experiment Station, 1896-1898. — Reports four dietary 

 studies of infants, one of the university football team during training, 

 and one of a chemist's family; also digestion experiments with an 

 infant on a milk diet, as well as a metabolism experiment in which the 

 balance of income and outgo of nitrogen was determined. 



Bulletin 85, pp. 51.— A Report of Investigations on the Digestibility 

 and Nutritive Value of Bread. — This bulletin is a progress report, 

 giving the results of experiments with men on the digestibility of 

 bread of various kinds when eaten alone, and when forming a part of a 

 simple mixed diet; artificial digestion experiments with the same sorts 

 of bread; a test of skim milk v. water for use in mixing dough; and 

 studies of the loss of nutrients in bread making and of methods of 

 determining metabolic nitrogen. 



Bulletin 89, pp. 77. — Experiments on the Effect of Muscular Work 

 upon the Digestibility of Food and the Metabolism of Nitrogen. — This 

 is a report on 16 experiments with men, undertaken for the purpose 

 of studying the effect of muscular work upon the digestibility of a 



