
FOOD INVESTIGATIONS. 119 
At the close of the latter the work was transferred to Middle- 
town, where it has been completed with the aid of the Station 
and of Wesleyan University. Some five hundred specimens 
have been analyzed, and the investigation thus made is more 
extensive than any similar one yet undertaken. 
The results of these analyses will be incorporated in the 
standard table above referred to as being now in preparation. 
INVESTIGATIONS WITH THE BOMB CALORIMETER. 
The study of food and nutrition has shown the need of 
learning the fuel-values of food materials, or in other words, 
the amounts of potential energy which they contain and which 
may be changed to heat or muscular power or other form of 
energy in the body. ‘The apparatus for this purpose is called 
the calorimeter. Investigations with a form of calorimeter 
were described in the Report for 1890. A form which has 
proven more satisfactory is the so-called bomb calorimeter. 
Hitherto the only satisfactory bomb calorimeter has been that 
devised by Prof. Berthelot in Paris, but its great cost; $1,000 
or more, which is due to the large quantity of platinum required 
for its construction, has prevented its general use. With the 
aid of Prof. Hempel, of Dresden, we succeeded in obtaining a 
bomb calorimeter which cost about $200, and has proved quite 
satisfactory. ‘his apparatus and the attempt to develop it into 
a form which, without sacrifice of accuracy and reliability, will 
be durable, convenient and made at a cost which will bring it 
within the reach of ordinary laboratories, are described in the 
Report of this Station for 1894.. The efforts in this direction 
are being materially aided by the U. S. Department of Agricul- 
ture. Although some details of construction and manipulation 
still need to be worked out and tested, the results are already 
highly satisfactory. 
RESPIRATION CALORIMETER. 
Research upon nutrition has reached the point where the 
study of the application of the laws of the conservation of 
matter and of energy in the living organism are essential. 
That is to say, we must be able to determine the balance of in- 
come and outgo of the body, and this balance must be expressed 
both in terms of matter and of energy. For this purpose a 
