456 REPORT OF OFFICE OF EXPERIMENT STATIONS. 



excretory products necessitates some means for measuring the heat 

 of combustion of these materials, and in connection with the nutri- 

 tion investigations a bomb calorimeter has been perfected which 

 has proved very satisfactory. 



Numerous studies have been undertaken of the changes brought 

 about and losses sustained when foods of different sorts are cooked in 

 different ways, the principal food materials included in this work 

 being bread, A^egetables, and meat. Canning and preserving fruits and 

 vegetables may be regarded as special applications of cooking proc- 

 esses, and much experimental work has been done along these lines 

 with a view to the elaboration of satisfactory household methods. In 

 general, it may be said that in connection with the different lines of 

 work mentioned it has been necessary to devise and perfect experi- 

 mental methods, as at the time the investigations were first under- 

 taken the amount of work which had been done in the United States 

 and elsewhere along; such lines was not verv considerable. 



The same period which has witnessed the development of the nutri- 

 tion enterprise has seen a great interest aroused in the teaching of 

 home economics in schools and colleges, and nutrition is one of the 

 main divisions included in this subject. As the nutrition investiga- 

 tions have supplied a great deal of data necessary to teachers of 

 home economics, and as the office was already closely identified with 

 other educational enterprises, it was almost inevitable that the peda- 

 gogics of nutrition should receive attention and become an increas- 

 ingly important part of the nutrition enterprise. 



The preparation of reports of investigations and popular summa- 

 ries has also constituted an important feature of the work. Some 

 60 technical bulletins and over 50 Farmers' Bulletins and other popu- 

 lar summaries have been issued. These are described more at length 

 in the following section. Information is also supplied by corre- 

 spondence, a feature which has grown to large dimensions, and, so 

 far as circumstances permit, by means of lectures and conferences. 



An idea of the character of the nutrition work at the present time 

 may be gathered from an account of what was done during the last 

 fiscal year and of the plans formulated for w^ork during the next 

 fiscal year, which will be found on pages 32-37 of this report. 



Very recently the respiration calorimeter has been adapted to the 

 study of problems of vegetable physiology, and in cooperation with 

 the Bureau of Chemistry interesting studies are being made of the 

 respiratory exchange and energv' output of ripening fruit (bananas). 



This kind of work opens up a new and very promising field of use- 

 fulness for the apparatus and methods. 



