PREVIOUS INVESTIGATIONS. 35 



Johansson, Billstrom, and Heijl 1 report respiration experiments with 

 men in which cane sugar, dextrose, and levulose were used. Following 

 the usual Stockholm technique, the sugars were taken in varying 

 amounts with varying quantities of water. The carbon-dioxide 

 output at first seemed to increase proportionately with the amount of 

 sugar taken. With larger portions, i. e., 200 grams of cane sugar, the 

 increase was relatively smaller. Cane sugar and levulose had about 

 the same effect, while dextrose had a much smaller effect than either 

 levulose or cane sugar. In an attempt to explain the difference between 

 levulose and dextrose the authors assume that the rapidity of combus- 

 tion is greater and the rapidity of storage as glycogen less for levulose 

 than for dextrose. They conclude that the ingestion of carbohydrates 

 actually increases the energy transformation, unless it is assumed that 

 there is a fat formation with a cleavage of carbon dioxide. 



Cronheim, 1905. Employing the Zuntz-Geppert technique, Cron- 

 heim 2 reports the study of the influence of a highly nitrogenous (81.2 

 per cent protein) preparation, somatose, upon the metabolism. He con- 

 cludes that the increased metabolism after somatose, designated by him 

 in accordance with the usage of the Zuntz school as Verdauungsarbeit, 

 is less than that after meat containing a corresponding amount of 

 nitrogen. A number of meat experiments are reported in which he 

 finds that after 130 grams of meat the increase in the oxygen consump- 

 tion in 7 hours equals 5,790 c.c., corresponding to a total energy output 

 of 27.73 calories, or 20.9 per cent of the energy value of the meat. 

 With an amount of somatose containing as much nitrogen as the 130 

 grams of meat, he finds that the increase was but 9.29 per cent of the 

 energy of the ingested material. With meat the main increase in 

 metabolism occurred in the second to the fourth hour, but with soma- 

 tose it did not occur until later. These time relations were likewise 

 observed in the rate of excretion of nitrogen in the urine. 



Johansson, 1908. In 1908 Johansson 3 made another important con- 

 tribution to the study of the influence of carbohydrates upon metabo- 

 lism. Using the Sond6n-Tigerstedt respiration chamber in Stockholm 

 with a large number of subjects, he made experiments with various 

 sugars and accurately determined the increment in the carbon-dioxide 

 production. It is greatly to be regretted that Johansson's most valuable 

 discussion could not have been based upon measurements of the oxygen 

 consumption made simultaneously with the carbon-dioxide measure- 

 ments. In this way a suggestion could have been obtained as to the 

 probable relationship between the three factors which may enter into 

 such a carbon-dioxide increment, {. e., first, the substitution of a katab- 

 olism consisting mainly if not exclusively of carbohydrate; second, 



Johansson, Billstrom, and Heijl, Skand. Arch. f. Physiol., 1904, 16, p. 263. 

 2 Cronheira, Arch. f. d. ges. Physiol., 1905, 106, p. 17. 

 'Johansson, Skand. Arch. f. Physiol., 1908-09, 21, p. 1. 



