OFFICE OF EXPERIMENT STATIONS. S8l 



In connection with the respiration calorimeter, a number of very 

 important changes have been made. Early in the fall of 1901 jDlans 

 were drawn for rebuilding the wooden portion of the calorimeter proj)er, 

 with a view to securing more perfect insulation, easier control of the 

 heating and cooling devices, and accessibility of the interior parts. 

 As remodeled the exterior wooden walls were diminished in size and 

 number, and altogether the system is much less cumbersome than 

 before. The apparatus is now constructed so that it can be entirely 

 taken apart, the copper box rolled out on two tracks, and both the 

 inside and the outside of the respiration chamber made very accessi- 

 ble. This has already proven of great value in making alterations 

 either in the thermal junctions or heating and cooling systems. 

 Entirely new arrangements for the heating and cooling circuits have 

 been installed, including a new form of rheostat for varying the intensity 

 of the electric cui-rent passing through the heating wires. An espe- 

 cially effective piece of apparatus is the new form of switch devised 

 by the mechanician, Mr. S. C. Dinsmore. This switch simplifies 

 greatly the observations on the thermo-electric systems, and thus 

 increases their rapidity and accuracy. It was used in the experiments 

 of the year 1901-1902. 



A number of minor changes have also been made in the general 

 manipulation of the apparatus. 



Inasmuch as the method generallj' employed for determining water 

 in food samples is defective, a special investigation was conducted to 

 determine if possible a satisfactory method for removing water from 

 substances without causing any disintegration of the chemical mole- 

 cules of the ingredients of the food. This was a continuation of some 

 work undertaken a number of years ago. The most satisfactory 

 results Avere obtained by use of a vacuum desiccator. A description 

 of a simple method for obtaining a ver}' satisfactory vacuum was 

 published in the American Chemical Journal for May, 1902. 



A large amount of editorial work has been necessary to prepare the 

 reports of the collaborators in different parts of the countrj^ for pub- 

 lication. In every case the figures furnished have been verified to 

 guard against the possibility of error, the literature of the subject has 

 been reviewed, and text has been amplified and edited as seemed 

 expedient. 



A considerable amount of work has been done in collating and 

 abstracting the results of the work of other investigators and putting 

 the material in form for future publication. For the administrative 

 work centered at the Middletown office and the correspondence 

 regarding the nutrition investigations, as well as the clerical labor 

 required in calculating and editino'the results of the metabolism exper- 

 iments and other investigations, a considerable force is needed. 



Prof. C. D. Woods, of the University of Maine, at Orono, has studied 

 the digestibility and nutritive value of flour. During the past two 

 years he has made 33 digestion experiments with bread made from 

 different grades of wheat flour from the same lots of wheat. In con- 

 nection with his work Professor Woods has also made an extended 

 stud}- of methods of investigation, including the separation of feces. 

 In addition to the digestion experiments Professor Woods has made 

 4 dietary studies with lumbermen. These men performed severe 

 work under unusual conditions. It is believed the results of the 

 studies will be of interest in the study of the relation of diet to mus- 

 cular work. 



Prof. Harry Snyder, of the University of Minnesota, at Minneap- 

 olis, has made investigations along the same lines as those followed 



