NUTRITION INVESTIGATIONS. 65 



matpi'ials under diffcront conditions, to ^'wc ()})poitunity for compari- 

 son with tho data obtained by investij^ators in other countries, and to 

 assist in estalilishinjj a ijeneral dietary staiuUird. 



The dig-estion experiments have also been carried on in diti'crcnt 

 parts of the United States under var3'ing- conditions. These experi- 

 ments have been made in order to obtain dahi with reference to the 

 dig-estibility of various chisses of food materials, the amount of the 

 material consumed which is made available to the body, and the estab- 

 lishment of stiindards. Meats, lej^umes, cereals, fruits, and nuts have 

 been the especial subjects of experiments the past year. The digestion 

 experiments with meat have included the study of the influence of 

 cooking, as well as of age and breed of animal, etc., upon the digesti- 

 bilitv. The dig'estion experiments with cereals have included the 

 study of the effect of ditierent methods of the milling of flour upon 

 the digestibility of bread made from it. 



The cooking experiments have been made only with meat, and have 

 included the study of the effects of cooking upon the flavor, palatability, 

 and digestibilitj' of the meat, beef being usually used for the purpose. 



The metabolism experiments have been of two general sorts: (1) 

 Those in which the income and outgo of nitrogen were studied, and (2) 

 those which took account of the income and outgo of nitrogen, car- 

 l)on. and energy. The former have been made in connection with all 

 the digestion experiments. The latter have been made onl}' at ^liddle- 

 town, Coim., as they necessitate the use of the respiration calorimeter. 



In connection with all investigations some analytical work, both 

 physical and chemical, was, of course, necessary for the successful 

 carrying out of the experiments. The development of apparatus and 

 methods has received nmch attention the past 3'ear, especially at Mid- 

 (lletown. A large amount of editorial work, including calculations 

 and the veriHcation of data, has also been required at both A\'ashing- 

 toii and Middletown to prepare the results of the investigations for 

 publication in both technical and popular form. 



THE WORK AT DIFFERENT PT-ACES. 



The Washington oflice, in addition to editorial work, has had 

 general supervision of the plans and expenditures of the nutrition 

 investigations during the past year. The results of such incpiiry in 

 this country and in Europe, not generall}' available, and bibliographical 

 data, have been collected, and the current literature on the subject of 

 nutrition has been reviewed and abstracts made, partly for use in the 

 Experiment Station Record and partly for such other purposes in con- 

 nection with the general incjuiry as seemed desirable. 



In cooperation with the I)e])artment of the Interior, some ver}' 

 interesting dietary studies have been carried on in the Government 



S. Doc. 148, 58-2 5 



