Carbon Dioxide. 441 



The next series of experiments on the total carbon dioxide output of fasting 

 men was made by Pettenkofer & Voit. 127 In two 24-hour experiments when 

 the man was at rest, the elimination of carbon dioxide as measured in the 

 Pettenkofer apparatus was 738 and 729 grams for 24 hours. During a third 

 24-hour fasting experiment the subject performed considerable muscular work 

 and the carbon dioxide production increased to 1187.5 grams. 



Sadovyen (2), with the Pashutin respiration apparatus, measured the carbon 

 dioxide elimination of a fasting man in two experiments, one of 2 days and 

 the other 4 days. In this series of experiments, the subject did not remain in 

 the chamber during the entire 24 hours, the experimental periods being gener- 

 ally of 9 to 10 hours' duration. No water was consumed during the first 

 experiment. The total carbon dioxide production for the 2 days was 755 and 

 746 grams, respectively, and for the 4 days of the second experiment the 

 amounts, computed on the basis of 24 hours, were 810, 795, 620, and 613 

 grams, respectively. 



In studying the production of heat of a healthy man in a condition of com- 

 parative rest, Likhachev "* included a study of the carbon dioxide output of 

 man during inanition. The subject remained inside the Pashutin respiration 

 apparatus for over 24 hours and the records for the day were therefore 

 unbroken. The amount of carbon dioxide produced during this experimental 

 day was 596 grams or 10.7 grams per kilo of body weight. 



The carbon dioxide production of the fasting subject J. A. (9) was 

 determined by means of the Tigerstedt respiration apparatus. As in the 

 experiments of Sadovyen, the subject did not remain within the chamber con- 

 tinuously, but spent about two hours each day outside. Computed on the 

 basis of 24 hours, the carbon dioxide elimination measured by the apparatus 

 was on the 5 days 691, 658, 632, 621, and 608 grams, respectively. 



The fasting experiments made in this laboratory and previously reported ia> 

 included determinations of the carbon dioxide. During experiments Nos. 36, 

 39, and 42, each of 24 hours' duration, the production was 711, 649, and 620 

 grams, respectively. The amounts eliminated for the 2 days of experiment 

 No. 51 were 703 and 698 grams, respectively. 



Since the production of carbon dioxide and the metabolic activity are, in 

 general, largely proportional to the body-weight, these older experiments may 

 perhaps be better compared by noting the amounts of carbon dioxide per kilo- 

 gram of body-weight and per square meter of body surface. The total carbon 

 dioxide production for the older experiments is given in table 221, together with 

 the amounts per kilo of body-weight and per square meter of body surface. 



12T Zeit. f. Biologie (1866), 2, p. 478. 



128 Dissertation (Russian), 1893, St. Petersburg. 



129 U. S. Dept. of Agr., Office of Expt. Sta. Bui. 136. 



