GENERAL DETAILS. 121 



GENERAL DETAILS REGARDING THE RESEARCH. 



The experiments in 1905, 1906, and 1907, included in this research on 

 the effect upon the metabolism of the ingestion of food, were made at 

 Wesleyan University, Middletown, Connecticut, and those subsequent 

 to 1907 in the Nutrition Laboratory in Boston. Only the respiration 

 calorimeter was used in the Middletown experiments. In the Boston 

 experiments not only the chair and bed respiration calorimeters were 

 employed, but also two forms of respiration apparatus i. e,, the 

 universal respiration apparatus and the Tissot respiration apparatus. 

 With the calorimeters, the carbon-dioxide production, the oxygen 

 consumption, and the heat production were determined; with the 

 respiration apparatus, determinations were made only of the respir- 

 atory exchange, the heat production being obtained by indirect 

 calorimetrj r . The several apparatus have been fully described else- 

 where ; brief descriptions are included in this publication. 1 The general 

 plan of experimenting has been given in the preceding section ; the rou- 

 tine with the various apparatus has also been outlined with more or less 

 detail in the discussion of the results of the experiments. 



In the Middletown calorimeter considerable freedom of movement 

 was possible. In the 24-hour experiments with this apparatus the sub- 

 ject was able to carry out the ordinary routine of a day, restricted only 

 by the confines of the chamber and the experimental requirements for a 

 minimum amount of activity. In the waking hours he sat in a chair; 

 in the sleeping periods he lay on the bed. During the 8-hour experi- 

 ments with the same apparatus he sat quietly in a chair. In the chair 

 calorimeter in Boston the subject also sat in a chair for the entire 

 experimental period and was instructed to reduce all movement to 

 the minimum. In all these apparatus the water and urine vessels and 

 telephone were placed conveniently near the subject, so that they could 

 be used with the least activity possible. In the bed calorimeter the 

 subject lay on an air mattress with few or no major changes of position. 

 In the experiments with the two respiration apparatus the subject lay 

 on a couch, practically without movement, during the periods. 



In the Middletown calorimeter experiments the individual periods 

 were usually 2 hours in length; in the Boston calorimeter experiments 

 they were shortened to 1 hour and in a few instances to 45 minutes. 

 With the universal respiration apparatus the periods ordinarily approxi- 

 mated 15 minutes in length; with the Tissot apparatus the periods were 

 generally shorter. The observations in the experiments with the two 



'For a description of the Middletown calorimeter, see Atwater and Benedict, Carnegie Inst. 

 Wash. Pub. No. 42, 1905. For the chair and bed calorimeters, see Benedict and Carpenter, 

 Carnegie Inst. Wash. Pub. No. 123, 1910. For the universal respiration apparatus, see Benedict, 

 Deutsch. Arch. f. klin. Med., 1912, 107, p. 156; Carpenter, Carnegie Inst. Wash. Pub. No. 216, 

 1915. For the Tissot respiration apparatus, see Tissot, Journ. de physiol. et de path, gen., 1904. 

 6, p. 688, and Carpenter, Carnegie Inst. Wash. Pub. No. 216, 1915, p. 61. 



