INGESTION OF PROTEIN DIETS. 299 



either the amount or the duration of the effect upon the metabolism 

 due to the ingestion of this amount of nitrogen. The general effect of 

 100 grams or more of plasmon, together with 200 c.c. or over of skim 

 milk, is to increase the heat output considerably above the basal metab- 

 olism for at least 10 hours. 



SUMMARY OF RESULTS OF EXPERIMENTS ON INGESTION OF 



PROTEIN. 



A general examination of the details of the experiments discussed 

 in the preceding part of this section shows conclusively that following 

 the ingestion of protein there is a distinct increase in the metabolism 

 which may persist for a considerable period of time. In an attempt to 

 establish a quantitative relationship between the amounts of protein 

 ingested and the subsequent increments in the metabolism, and like- 

 wise to study the time relations, we have summarized in table 230 the 

 results of the calorimeter experiments. The data for heat produc- 

 tion in the respiration experiments have already been presented in 

 table 215. (See page 284.) 



Most of the experiments were made with animal protein, these 

 including the large number in which beefsteak was ingested. Even 

 the beefsteak experiments in which small amounts of bread and potato 

 chips were taken may, for reasons previously discussed, be considered 

 as primarily animal-protein experiments. The experiments with plas- 

 mon and skim milk likewise showed the influence of animal protein 

 upon the metabolism. In the experiments with gluten bread and skim 

 milk the effect of a combination of vegetable and animal proteins was 

 studied, but the greater part of the nitrogen was supplied by the 

 gluten. The only experiments with pure vegetable protein were those 

 with glidine, but with two exceptions the amounts of nitrogen in the 

 glidine ingested were relatively small. 



It is somewhat difficult to present in tabular form the results of 

 experiments extending over a period of many years, which were made 

 with different apparatus, very considerably different amounts of food, 

 and varying experimental periods. The table is, however, reasonably 

 self-explanatory. Special attention should be called to the consider- 

 able variations in the length of the individual periods in the experi- 

 ments, these being shown in the first column with the initials of the 

 subject. In all cases they were 2 hours, 1 hour, or 45 minutes in length. 

 The total increments in carbon-dioxide production, oxygen consump- 

 tion, and heat production during the entire period of observation are 

 given in the next to the last column ; in the last column may be found 

 the percentages of increment above the basal values for the same peri 



A positive increment was obtained in all of the experiments except 

 in that with F. M. M., January 20, 1910. Even in this experiment 



