70 EXPERIMENT STATTON RECORD. 



marks ($77. 152), or 34.87 marks ($8.30) per hectare. The cost for the collection of 

 nun moths for three years is given as follows: 1894, 794 moths, 110.49 marks; cost 

 per moth, 14 pfennigs; 1895, 701 moths, 137.12 marks; cost per moth, 20 pfennigs; 

 1890, 398 moths, 03.11 marks; cost per moth, 16 pfennigs. The average number 

 of moths captured per hectare in the three years was 20, 33, and 19, respectively. 



F00PS— ANIMAL PRODUCTION. 



Comparison of the thermogenetic or dynamogenetic power of 

 simple food stuffs with their nutritive value, A. Ohauveau (Compt. 

 Rend. Acad. Sci. Paris, 125 {1897), No. 25, pp. 1070-1078, <l(jms. 2).— 

 Three experiments with a dog made by the author's usual methods ' are 

 reported with but few details. In the first experiment the dog was fed 

 a basal ration of meat to which isodynamic quantities of lard and sugar 

 (1:2.373) were added in different periods. The quantities fed were — 

 meat 400 gin., lard 51 gm., and sugar 121 gm. 



In the second experiment to a basal ration of meat, fat (lard) and 

 sugar were added in different periods in quantities intermediate between 

 their isodynamic and isogly oogenetic values; that is, in the ratio of 

 1:1.83. The amounts fed were — meat 500 gm.,lard 110 gm., and sugar 

 200 gm. 



In the third experiment to a basal ration of 500 gm. meat was added 

 110 gm. fat or 1G8 gm. sugar; that is, the amounts of sugar and fat were 

 proportional to their isoglycogenetic values (the amount of glycogen 

 which could be formed from each). In all the experiments some muscu- 

 lar work was performed. 



Among the conclusions reached were the following: The heat of com- 

 bustion (often assumed to represent the real nutritive value) of sugar 

 and fat is not the measure of the energy which the two substances fur- 

 nish for the production of force in the animal body. There is a consid- 

 erable discrepancy between the two values. If the heat of combustion of 

 cane sugar is 1, that of fat is 1.52, and not 2.373, the isodynamic value 

 ordinarily assumed. ( )n the other hand, sugars and fat possess the same 

 nutritive value when consumed in quantities proportional to the amount 

 of glycogen which they can form. Thus, 1.52 gm. of cane sugar or 1 

 gm. of fat yields 1.G1 gm. of glycogen, in the one case by hydration and 

 in the other by oxidation. The different nutrients are not directly 

 sources of potential energy, i. e., of energy in the working muscle. 

 Glycogen alone (which permeates the muscles) can be regarded as the 

 source of muscular work. It is continually used up and renewed and 

 equilibrium maintained. 



It is needless to remark on the importance of the bearing of these 

 deductions on the value of sugar as a nutrient. 



'The author has devised a respiration apparatus which permits the measurement 

 of the inspired and respired air and a determination of the respiratory quotient. 

 The respiratory movements are also recorded graphically. The amount of muscular 

 work performed may be measured.— Arch. Physiol. Norm, et Path., 5. ser., 8 (189G), 

 pp. 563-571. 



