12 FOOD INGESTION AND ENERGY TRANSFORMATIONS. 



as much regularity as possible. The effects from the food, therefore, 

 were not remarkable. Apparently the food taken simply kept the 

 carbon-dioxide production up to the standard and occasionally increased 

 it somewhat, certainly never depressed it. Prout found that fermented 

 liquor, which was occasionally taken, always depressed the carbon- 

 dioxide production. Tea had a like depressing effect, for after 3 or 4 

 ounces of strong, cold tea he found a considerable diminution in the 

 carbon-dioxide produced. As Prout was much surprised to note 

 the depressing effect of alcohol and all liquors containing it, he made a 

 number of observations on alcoholic liquors, which invariably gave 

 the same result, i. e., a depression of the carbon-dioxide excretion. In 

 this consideration of his results, it is important to bear in mind the fact 

 that his observations were solely on the percentage of carbon dioxide 

 in the air. Little evidence is given in this paper to lead one to think 

 that he had any conception of the total amount of the carbon-dioxide 

 excretion. Scharling, 1 in citing Prout's experiments, concludes from 

 the figures given for pulse rate that there really was a greater carbon- 

 dioxide production after the ingestion of food than Prout noted. 



Fyfe, 1814- At about the same time as Prout's experiments, a 

 number of observations were made by Andrea Fyfe, 2 of Edinburgh, 

 which form the basis of a communication made by Prout in 1814. 3 

 Like Prout, Fyfe dealt exclusively with the percentage of carbon 

 dioxide in the expired air. The expired air was collected in a bell- 

 jar holding approximately 2.5 liters; the proportions of carbon dioxide 

 and oxygen were then determined by means of a Hope eudiometer 

 with the use of lime-water and sulphuret of lime. In an extensive 

 series of experiments in which vegetable diets were given, Fyfe reports 

 that the percentage of carbon dioxide fell from 8.5 per cent before the 

 food experiment to about 4.5 per cent on the seventh and eighth days 

 of the test. The experiments with animal diet lasted 8 days; on the 

 fourth day the carbon dioxide was 7 per cent and on the seventh 

 and eighth days 5 per cent. A repetition of the experiment gave 

 values for the carbon-dioxide content on the third, fourth, fifth, sixth, 

 and seventh days of 6 to 7, 7, 9, 5, and 8 per cent, respectively. When 

 wine was taken, the carbon dioxide in the expired air was reduced in 

 one experiment to between 2 and 3 per cent, and in another to 5.75 

 per cent. 



Coathupe, 1839. Twenty-five years after the experiments of Fyfe, 

 Coathupe 4 made a series of observations on the products of respiration 

 at different periods of the day, employing much the same apparatus 



'Scharling, Ann. d. Chem. u. Phann., 1843, 45, p. 214. He speaks of Prout's results as being 

 published in the Journ. f. Chem. u. Physik von Schweigger, 1815, 15, p. 65. 



J Fyfe, Dissertatio Chemico-Physiologica Inauguralis de Copia Acidi Carbonic! e Pulmonibus 

 inter respirandum evoluti, 1814. 



*Prout, Annals of Philosophy, 1814, 4, p. 331. 



4 Coathupe, Phil. Mag., 1839, 3d ser., 14, p. 401. 



