FOODS — ANIMAL PRODUCTION. 



865 



exercise; and the fourth was a period of quite severe muscular activity. 

 The subject spent 3 hours each day iu raising aud lowering 1 a 5.7 kg. 

 iron weight by means of a pulley. 



The income and outgo of nitrogen and carbon and the fuel value of the 

 food, urine, and feces are recorded in full for each of the experimental 

 periods. In the following table the results for the balance of income 

 and outgo of nitrogen and carbon are summarized : 



Income and outgo of nitrogen and carbon. 



Laboratory janitor: Rest 



(2 days) 



Do 



Chemist: Light mental 



work (5 days) 



Physicist: 



Ki-st (lg days) 



Mental work (3 daj s) 



Rest (3 days) 



Muscular" work (3 



days) 



Rest (lg days) 



Whole experiment (12 

 days) 



Nitrogen. 



In 

 food. 



Gms. 



45.4 

 38.4 



26.3 

 48.6 

 48.6 



48.6 

 22.3 



Tn 



urine. 



Oms. 



39.2 

 36. 1 



23.2 

 39.4 



37.4 



42.4 

 21.5 



In 

 feces. 



1.8 



3.2 



4.5 



2.3 

 4.2 

 4.2 



4.2 

 l.'J 



(iain 

 ( + ) or 



loss 



(-)■ 



H- 4.4 



— C.9 



::. :; 



(I. s 



5 



I 7.0 



f- 2.0 



— 1.1 



Carbon. 



In 



food 



I, IDS. 



57S. fi 

 521.2 



396.7 

 7H2. 3 

 732.3 



732.3 

 335.6 



2, 929. 2 



In 

 urine. 



Q HIS. 



22. 7 

 28. 6 



13.5 

 26. 3 



32.2 



30. 1 

 17.2 



In 

 feces. 



<; ins. 



18.0 

 19.8 



17.1 

 31.5 

 31.5 



31.5 



14.4 



Iu res- 

 pira- 

 tory 

 prod- 

 acts. 



(i ins. 



428.2 

 435.1 



1,099.6 



?76. 2 

 696.6 

 713.2 



1,114.6 



336.6 



3, 237. 2 



Cain 



(+) or 



loss 



(-). 



dins. 



[ 109.7 

 I- 37.7 



— 10.1 



— 22. 1 



— 44.6 



—443. 9 



— 32.6 



—555. 3 



From the income and outgo of nitrogen and carbon the gain or loss 

 of protein and fat was calculated. 



"The experience here obtained emphasizes the desirability of longer experimental 

 periods than have been customary in experiments of this class. Although a consid- 

 erable number of respiration experiments have been made with animals and man, the 

 periods have rarely exceeded 21 hours. 



"The prospects for obtaining a satisfactory balance of income and outgo of energy 

 are, on the whole, decidedly encouraging. The determinations of heats of combus- 

 tion by the bomb calorimeter are eminently satisfactory, and there seems to be good 

 ground to hope that ultimately the measurements of heat given off from the body 

 may also prove sufficiently accurate for such purposes. . . . Experience in this lab- 

 oratory since the above experiments were made have yielded results agreeing very 

 closely, indeed, with the theoretical figures. 



"The results of these experiments and of similar investigations elsewhere bring 

 out very clearly the difference in the amounts of nutrients and energy required by 

 the organisms of different persons under different conditions, and confirm the results 

 of previous inquiry in showing that muscular labor is performed at the expense of 

 the fats, sugars, and starches. They also make it clear that the body may draw upon 

 protein for this purpose, although it has not yet been determined just what are the 

 conditions under which this is done." 



The chemistry of the corn plant, F. T. Shutt ( Canada Expt. Farms 

 Bpts. 1896, -pp. 208-211). — Analyses are reported of a number of varieties 

 of corn (whole plant) in the following stages of growth: Tasseling, 

 silking, early milk, late milk, and glazing. The amounts of the different 

 constituents per ton and per acre furnished at the different periods of 



