80 MUSCULAR WORK 
10 experiments was 3.68 c.c. per minute per kilogram of body-weight, while 
the last experiment on April 16 gave an oxygen consumption of 3.61 c.c. per 
minute per kilogram of body-weight. The general inference from these data 
would thus be that training influenced the metabolism but little in this series 
of experiments. It should be taken into consideration, however, that the 
subject was a trained bicyclist, and in good condition when he began the work. 
In general, this subject was inclined to eat heartily, having a decided 
preference for meat. He several times suggested that he would have been 
able to do considerably more work if he could have had a hearty meal before 
the experiment, instead of coming to the laboratory without breakfast. 
In fact, the subject found it somewhat difficult to adjust himself to this 
feature of the routine, although towards the end of the experimenting he 
became accustomed to it. Usually he ate a full meal about noon and a 
second about 7 h 30 m p.m., occasionally but not often taking food later in the 
evening. He drank no alcoholic liquors, and while he smoked cigars and 
cigarettes considerably in the first part of the study, later he practically 
ceased, because the mucous membrane was somewhat irritated by the fre- 
quent use of soapsuds over the mouth. While it was found impracticable 
to control the diet of the subject when he was outside of the laboratory, the 
special study previously referred to of the influence on the metabolism of 
varying amounts of carbohydrate in the diet supplied sufficient data for 
intelligent discussion. This phase of the subject is given treatment elsewhere. 
THE CHARACTER OF THE KATABOLISM DURING MUSCULAR WORK AS INDICATED 
BY THE RESPIRATORY QUOTIENT. 
A critical analysis of the respiratory quotients secured in this research 
permits an estimate as to the character of the katabolism before, during, and 
after work, this being one of the main objects of the study. Chauveau was 
one of the earliest to recognize the significance of the respiratory quotient 
as an index of the character of the katabolism, and as the foremost advocate 
of the belief that all muscular work is accomplished at the expense of carbo- 
hydrate combustion, his views should be presented somewhat extensively. 
Theobies op Chauveau and Zuntz as to the Character of the Katabolism 
during Muscular Work. 
One of the most striking pieces of evidence that Chauveau has presented 
in favor of his theory of a selective carbohydrate combustion during muscular 
work is an experiment made on M. Tissot. 6 In this experiment the subject 
was without food, the last meal having been taken 16 hours before. The work, 
which was continuous, consisted of going up and down a long staircase in 
the laboratory, the time for the ascent and descent being always the same. 
At the end of 70 minutes the subject had done about 29,000 kilogrammeters 
of positive work, the amount of negative work, according to Chauveau's 
computations, being similar. At the end of this time the subject was com- 
pletely fatigued. During the experiment the expired air was collected 6 
times in a Chauveau-Tissot apparatus, each sample requiring precisely 5 
minutes. The respiratory quotients, which were determined at different 
periods during the work, were as follows : 
o See p. 88. * Chauveau, Comptes rendua, 1896, 122, p. 1163. 
