202 FOOD INGESTION AND ENERGY TRANSFORMATIONS. 



eral picture shown for bananas and sugar is that of a very pronounced 

 increase in heat production following their ingestion, which may rise 

 in individual periods to a peak of 34 per cent, with a total increment 

 above the basal value as high as 24 per cent and frequently 15 or more 

 per cent, values which are considerably above those normally noted 

 with pure carbohydrates. The effect following the ingestion of cane 

 sugar is very pronounced; a considerable effect is likewise found with 

 bananas. The high values obtained with the combined bananas and 

 sugar point definitely to the conclusion that we have here an effect 

 due to cane sugar which is superimposed upon the effect due to the 

 large amount of carbohydrate taken simultaneously in the form of 

 fruit. 



The experiments with bananas without sugar gave results which 

 are irregular; two showed a measurable increment, while in the other 

 no increment was obtained. The two experiments with popcorn 

 indicate a distinctly higher metabolism as a result of the ingestion of 

 this material. But one experiment was made with rice, a fact which is 

 to be regretted, since the slight increment noted, namely, 7 calories, 

 should be confirmed. It is evident that our section of this research 

 dealing with carbohydrates of a gross texture and the possible effect 

 of roughage in the diet is altogether too limited for adequate discussion. 



RESPIRATION EXPERIMENTS. 



As the research on the influence of the ingestion of food progressed, 

 it became evident that measurements of the metabolism in short 

 periods were essential, for many of the experiments indicated a some- 

 what rapid change in the character of the metabolism following the 

 ingestion of carbohydrate. Experiments with periods of sufficiently 

 short duration to show this rapid change were impracticable with an 

 apparatus so large as the respiration calorimeter in Middletown. 

 With the development and subsequent completion in the Nutrition 

 Laboratory of the so-called "universal respiration apparatus" 1 observa- 

 tions could readily be made in short periods with fairly satisfactory 

 results. An extended series of such experiments was begun in the fall 

 of 1910 and continued at intervals for several years. We are indebted 

 to Mr. H. L. Higgins 2 and Mr. L. E. Emmes for their kind coope- 

 ration, as the majority of the experiments made in 1911 were under 

 their immediate supervision. The experiments previous to 1912 were 

 made with the so-called "tension-equalizer" form of the respiration 

 apparatus, 3 which was later replaced by the spirometer type of the 

 same apparatus. Both types of the apparatus have been carefully 



'This apparatus is described in detail by Benedict, Deutsch. Arch. f. klin. Med., 1912, 107, 

 pp. 156-200; also Carpenter, Carnegie Inst. Wash. Pub. No. 216, 1915, pp. 21-53. 



'See, also, Higgins, Am. Journ. Physiol., 1916, 41, p. 258. 



'Carpenter, Carnegie Inst. Wash. Pub. No. 216, 1915, p. 21, and Benedict, Am. Journ. Physiol., 

 1909, 24, p. 345. 



