260 



.MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



Table 13. — Metabolism of em rgy. Avt rages of results of expt rum nix with ordinary and with alcohol dit > — ( lontinued. 



■ Estimated energy of material actually oxidized in the body. 



h In this average the muscular work of the work experiments is distributed over both the work and the rest 

 experiments, which is of course not strictly logical. 



The energy of net income given in the table above represents the energy of the material 

 actually oxidized in the body, as determined from the energy of the food, of the excretory products, 

 and of the body material stored or lost. The energy of outgo is that given off from the body in the 

 form of heat and external muscular work, as measured by the apparatus. According to the law 

 of the conservation of energy, the income and the outgo must be equal. From the comparisons 

 given in the table above it will be seen that, whether the diet did or did not contain alcohol, the 

 outgo was sometimes greater and sometimes less than the income, but the difference in every case 

 was far within the range of variation to be expected in physiological experiments of such nature 

 as these, so that the results may be considered as showing practical agreement. If we counter- 

 balance the variations by averaging the experiments in which alcohol formed part of the diet and 

 those without alcohol, we get the following results: 



Daily income "ml outgo of energy with and without alcohol. 



Diet. 



Energy of ma- 

 teria] oxidized 



in the body. 



Energy given 



..IV by the 

 bodv. 



Average 13 experiments, without alcohol. 

 Average 13 experiments, with alcohol 



t 'alories. 



2,717 

 2, 746 



Calorit s. 

 2. 723 



When the diet contained no alcohol, the energy of the proteids, fats, and carbohydrates burned 

 in the body, averaging 2.717 calories per day, was practically identical with the energy given oil' 

 by the body in the form of heat, or heat and (the heat equivalent of) external muscular work, 

 averaging 2,723 calories per day. When alcohol formed part of the diet the total energy of the 

 proteids, fats, and carbohydrates burned in the body, added to the energy of the alcohol, averaged 

 2.74d calories per day. and the energy given olf as heat, or heat and external muscular work, 

 averaged 2,752 calories per day. The total kinetic energy of outgo is equal to the total potential 

 energy of income, whether it be with ordinary diet alone, or with ordinary food and alcohol. 



To these results there can be but one interpretation. The energy which was latent or poten- 

 tial in the alcohol was wholly transformed in the body, was actually given off from the body, 

 and was exactly recovered as heat or heat and muscular work. Otherwise, how did the body 



