78 FOOD INGESTION AND ENERGY TRANSFORMATIONS. 



With both subjects there was an increase in weight between the two 

 groups of experiments. With A. L. L. the weight in 1906 averaged 

 67 kilograms and in 1907 it averaged 73.4 kilograms, this increment in 

 weight being approximately proportional to the increase noted in the 

 metabolism. With A. H. M. the weight increased from 63.8 kilograms 

 to 66.2 kilograms; this slight increase was by no means proportional 

 to the increase in the metabolism. Although the values for the metab- 

 olism have not been presented on the basis of per kilogram of body- 

 weight or per square meter of body-surface, it is obvious that with this 

 latter subject the metabolic level was distinctly higher in the second 

 group of experiments than in the first group. Accordingly, in deter- 

 mining the increment in the metabolism with food, it is impossible to 

 use an average of these basal values for comparison and we must 

 resort to a selection of data from the experiments made nearest in 

 point of time to the food experiments. 



A general examination of tables 23, 24, and 25 shows that there is a 

 distinct tendency for the 2-hour values to diminish as the day pro- 

 ceeds. Not infrequently the value for the first period of the day is 

 somewhat higher than the others. Inasmuch as nearly all of our exper- 

 iments were planned on the four 2-hour period basis, this point demands 

 special consideration. The general picture for the two subjects 

 A. L. L. and A. H. M. (see tables 23 and 24) shows a definite though 

 slight tendency for the metabolism to decrease as the day progresses, 

 this being especially noticeable in the fifth and sixth periods. On the 

 other hand, the average carbon-dioxide values for H. R. D. (table 25) 

 are constant, while the oxygen values show, if anything, a slight in- 

 crease; the values for the heat production are irregular. It should 

 be remembered, however, that in several instances, and particularly 

 with H. R. D., the average values for the later periods are not derived 

 from values obtained on the same day as the averages for the preceding 

 periods, and hence they do not represent consecutive 2-hour periods in 

 all instances. Furthermore, while there are variations in individual 

 periods, it is the average of all these values that is being discussed, and 

 these averages indicate truthfully the general trend of the metabolism. 

 The values for the subjects H. C. K, Dr. R., E. H. B., A. W. W., and 

 H. B. W. (see table 26) usually show more constancy in the first four 

 periods of the day, although in a number of cases those for the fourth 

 period are high, especially for the heat production. 



The average basal metabolism for each subject is recorded in table 

 27, in which are given the average values for the body-weight, the 

 carbon dioxide produced, oxygen consumed, heat produced, and nitro- 

 gen excreted in the urine per 2-hour period. The nitrogen values are 

 included in this table as an indication of the probable protein katabo- 

 lism in the experiments. In no instance was the diet controlled prior 

 to the experiment, although usually no food had been taken for at least 



