PREVIOUS INVESTIGATIONS. 



23 



therefore, show very sharply the increment due to food, but the oxygen 

 values appear to be practically unaffected by this factor. 



TABLE 3. Respiratory exchange in food and fasting experiments (Sadovyen). 



Hanriot and Richet, 1888. Hanriot and Richet 1 published a series of 

 observations upon the metabolism of a man before and after he had 

 taken various foods. The apparatus used by them is in principle 

 much simpler than any thus far devised, but unfortunately, owing 

 to certain technical difficulties, it does not meet modern demands for 

 accuracy. In a series of experiments from March 15 to April 1 with 

 this subject, who weighed 50 kilograms, a mixed diet was given, con- 

 sisting of bread, potatoes, beef, cheese, butter, sugar, wine, coffee, and 

 water. The day's diet contained 268.9 grams of carbon and 20.2 

 grams of nitrogen. In a following series of experiments the food, 

 somewhat less abundant, contained 230 grams of carbon. During the 

 experiments the subject was seated and awake, but no particular 

 attention was paid to muscular repose. The average values obtained 

 showed that he consumed 17.5 liters of oxygen per hour fasting and 

 18.9 liters of oxygen per hour 1 to 5 hours after food had been consumed. 

 The observers note that the maximum activity of the respiratory 

 exchange occurred 3 to 4 hours after a mixed diet. 



In the second paper 2 Hanriot and Richet give the results of another 

 study of the gaseous metabolism of this man. In a 2-day fast they 

 found that the respiratory exchange did not alter from the seventeenth 

 to the forty-sixth hours in other words, a base-line was reached. 



and Richet, Compt. rend., 1888, 106, p. 419. 



*Ibid., p. 496. 



