December 10, 1915] 



SCIENCE 



817 



square meter of surface are produced in 24 

 hours, 8.34 grams of cane sugar under- 

 going inversion and fermentation during 

 that interval. This reaction is independent 

 of the strength of the sugar solution within 

 the wide limits of 2.5 to 20 per cent. If 

 the strength of the solution be at the maxi- 

 mum of normal reaction, or twenty per 

 cent., the quantity of sugar utilized in 

 twenty-four hours would be contained in a 

 film 4/100 of a millimeter in thickness sur- 

 rounding the cells. A like analysis shows 

 that in man whose cells are bathed in a 

 medium containing 0.1 per cent, of sugar 

 the quantity necessary for the support of 

 life during one day would be contained in 

 a layer which if spread around the ceil 

 would be 5/100 of a millimeter in thick- 

 ness. 



From the calculation of the energy re- 

 quirement in the food for the life of a na- 

 tion to the energy liberated by a yeast cell 

 in its simple resolution of sugar into alco- 

 hol and carbon dioxide is indeed a far cry, 

 except as showing that the energy doctrine, 

 as enunciated by Eubner, unites the world 

 of living things. 



In 1912 I calculated that the heat pro- 

 duction of three quiet and sleeping dogs 

 was 759, 748 and 746 calories per square 

 meter of surface at an environmental tem- 

 perature of 26°, that a dwarf produced 

 775 calories per square meter of surface, 

 and that four out of five sleeping men in- 

 vestigated by Benedict showed an average 

 heat production of 789 calories per unit 

 of area. Only in the sleeping infant 7 

 months old investigated by Howland, did 

 the metabolism appear out of the ordinary 

 and reached a level of 1,100 calories, and 

 this factor was specifically pointed out as 

 indicating a higher metabolism in the 

 youthful protoplasm than is present in the 

 adult. 



When the Russell Sage Institute of Pa- 



thology constructed in Bellevue Hospital 

 an Atwater-Rosa calorimeter copied in 

 the main after the successful models of 

 Benedict, it became absolutely essential 

 that some criterion of normal metabolism 

 be established, as a basis from which one 

 could estimate whether the metabolism 

 of a patient under investigation was 

 higher or lower than the normal. The 

 severe criticisms of Benedict upon the 

 method of estimating heat production from 

 the unit of surface led to a very careful 

 review of all the evidence and to new ex- 

 periments. Du Bois, who took up this 

 work, has used an accurate and ingenious 

 method with which he has been able to 

 actually measure the surface area of nor- 

 mal men. He and Mr. Delafield Du Bois 

 have discovered that the formula hereto- 

 fore used for estimating the surface area in 

 man showed an average inaccuracy of 16 

 per cent, and a maximal variation from the 

 normal of 36 per cent., this being found in 

 very fat individuals. A new formula has 

 been evolved which gives an average varia- 

 tion of ± 1.5 per cent, and a maximal vari- 

 ation of ± 5 per cent. Using the older 

 formula of Meeh, the heat production per 

 square meter of surface is 833 calories dur- 

 ing 24 hours, but using the more accurate 

 formula of Du Bois that rises sixteen per 

 cent, to 953 calories. In normal adults of 

 various shapes and sizes this is the hasal 

 metabolism as measured when the individ- 

 ual is resting and before the administra- 

 tion of food in the morning. The variation 

 from this standard does not exceed 10 per 

 cent, in 90 per cent, of the cases. The 

 maximal variation is 15 per cent. 



The critical studies of F. G. Benedict 

 have been especially helpful in stimulating 

 the reconsideration of all the data and 

 methods in relation to this subject. Bene- 

 dict is in agreement with Carl Voit when 

 he concludes that the mass of active proto- 



