NUTRITION LABORATORY* 



Francis G. Benedict, Director. 



During the past year the equipment of the Nutrition Laboratory has been 

 increased considerably by purchase, and particularly by the construction of 

 special apparatus of our own devising. Preliminary investigations have 

 been carried out, aiming toward the solution of some of the innumerable 

 problems in human nutrition, and the investigations begun in previous years 

 have been continued and the results in large measure prepared for publi- 

 cation. 



ADDITIONS TO EQUIPMENT. 



While the respiration calorimeter, as originally built at Wesleyan Univer- 

 sity, marked a great advance in the study of physiological problems dealing 

 with the transformations of matter and energy, each year of experience sug- 

 gests changes in the apparatus of practical value for increasing its efficiency 

 or facilitating manipulation. To enable us to make such changes and im- 

 provements, a machine shop was included in the original equipment of the 

 laboratory. Certain alterations in the interior arrangement of the building 

 itself have also been made necessary by the demands for increased space re- 

 sulting from a larger use of the apparatus. 



RESPIRATION CALORIMETERS. 



During the past year a third respiration calorimeter has been built and 

 completely finished. This is somewhat larger than the calorimeters pre- 

 viously constructed and will accommodate a man lying down or standing 

 upright, and will permit a subject to work upon a bicycle ergometer. The 

 apparatus is designed for experiments of 24 or more hours' duration, and 

 thus provides for more extended observations than are possible with either 

 of the two calorimeters first constructed. The new calorimeter has not yet 

 been used for experiments with man, but has been satisfactorily tested elec- 

 trically and some preliminary trials have also been made by burning known 

 amounts of alcohol inside the chamber. 



During the latter part of this year the construction of a large respiration 

 calorimeter has been begun for the purpose of studying muscular work, par- 

 ticularly that in which the legs are used in the motion of forward progres- 

 sion and up and down an inclined plane. The structural-steel framework 

 and the copper lining or inside chamber of this respiration calorimeter have 

 been finished, and it is expected that the entire apparatus will be completed 

 within a year. 



* Situated at Boston, Mass. Grant No. 606. $26,378 for investigations and maintenance 

 during 1910. (For previous reports on work in nutrition see Year Books Nos. 2-8.) 



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