RESPIRATION CALORIMETERS FOR STUDYING THE 



RESPIRATORY EXCHANGE AND ENERGY 



TRANSFORMATIONS IN MAN. 



INTRODUCTION. 



The establishment in Boston of an inquiry into the nutrition of man 

 with the construction of a special laboratory for that purpose is a direct 

 outcome of a series of investigations originally undertaken in the chemical 

 laboratory of Wesleyan University, in Middletown, Connecticut, by the late 

 Prof. W. 0. Atwater. Appreciating the remarkable results of Pettenkofer 

 and Yoit * and their associates, as early as 1892 he made plans for the 

 construction of a respiration apparatus accompanied by calorimetric fea- 

 tures. The apparatus was designed on the general ventilation plan of the 

 above investigators, but in the first description of this apparatus f it is seen 

 that the method used for the determination of carbon dioxide and water- 

 vapor was quite other than that used by Voit. Each succeeding year of 

 active experimenting brought about new developments until, in 1902, the 

 apparatus was essentially modified by changing it from the open-circuit 

 type to the closed-circuit type of Eegnault and Eeiset. This apparatus, 

 thus modified, has been completely described ■ in a former publication. J 

 The calorimetric features likewise underwent gradual changes and, as 

 greater accuracy was desired, it was found impracticable to conduct calo- 

 rimetric investigations to the best advantage in the basement of a chemical 

 laboratory. With four sciences crowded into one building it was practically 

 impossible to devote more space to these researches. Furthermore, the in- 

 vestigations had proceeded to such an extent that it seemed desirable to 

 construct a special laboratory for the purpose of carrying out the calori- 

 metric and allied investigations on the nutrition of man. 



In designing this laboratory it was planned to overcome the difficulties 

 experienced in Middletown with regard to control of the room-temperature 

 and humidity, and furthermore, while the researches had heretofore been 



* Pettenkofer and Voit: Ann. der Chem. u. Pharm. (1862-3), Supp. Bd. 2, p. 17. 



t Atwater, Woods, and Benedict: Report of preliminary investigations on the 

 metabolism of nitrogen and carbon in the human organism with a respiration 

 calorimeter of special construction, U. S. Dept. of Agr., Office of Experiment 

 Stations Bulletin 44. (1897.) 



JW. O. Atwater and F. G. Benedict: A respiration calorimeter with appliances 

 for the direct determination of oxygen. Carnegie Institution of Washington 

 Publication No. 42. (1905.) 



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