NUTRITION INVESTIGATIONS. 31 



NUTRITION INVESTIGATIONS. 



The object and aim of the nutrition investigations as a whole is to 

 collect and spread information regarding the value as food of agri- 

 cultural products, both animal and vegetable, in such a way that the 

 producer, distributer, and consumer may be benefited. 



For experimental work in this subject special apparatus and 

 methods are required and these have been developed as the enterprise 

 has progressed. Of particular importance is the respiration calo- 

 rimeter, an instrument of precision for use in experiments with men. 

 It is possible with the aid of this apparatus to study with an accuracy 

 not otherwise attainable the effects of various foods and other factors, 

 as shown by changes in the income and outgo of matter and energy in 

 the body. 



The respiration calorimeter, which was brought to Washington 

 from Middletown, Conn., Avhere it had originally been built, has been 

 reconstructed in quarters assigned to nutrition investigations on the 

 ground floor of the east wing of the new Department of Agriculture 

 building. It was not found necessary or desirable to modify the 

 general lines on which the calorimeter was originally built, but in the 

 reconstruction man}- improvements in details were introduced which 

 make for simplicity, economy, and convenience of operation and for 

 accuracy in the results obtained. The accessory laboratory appliances 

 and equipment necessary for use in connection with the respiration 

 calorimeter experiments have also been installed, and the equipment 

 as a whole is being used in studies of the nutritive value of agricul- 

 tural products along lines in harmony with the general work of the 

 department. 



As a whole the enterprise involves cooperation with other bureaus 

 and the supplementing, and not the duplication, of their work where 

 it concerns the utilization as food for man of dairy products, cereal 

 pro<lucts, and other foodstuffs. 



Most families use cheese to a greater or less extent, but in the United 

 States it is the custom to use it in rather small quantities and more as 

 a condiment than as a staple article of diet, perhaps owing to a belief 

 that cheese in quantity disturbs digestion. This question has for 

 some time constituted an important feature of the nutrition investi- 

 gations, and it has been found that cheese is thoroughly digested when 

 eaten in quantity as a chief source of protein and fat in the diet and 

 that it does not produce physiological disturbances. To round out this 

 work information is needed regarding the ease of dir;estion of cheese 

 as compared with other staple foods, and this question is being studied 

 with the respiration calorimeter. As was the case in earlier work, 

 cheese made and cured in different ways will be used and the different 

 varieties will be compared with each other and witli meat, bread, and 

 other standard food products. 



