464 



Mr. W. North. The Influence of 



machines than others, i.e., differences of weight and all else being 

 taken into consideration. One man will do a given amount of work 

 npon a given diet, which to another would be simply impossible. I 

 have had ample opportunity for observing this kr the training of 

 boats' crews in Cambridge, and I was particularly struck by the com- 

 plete absence of any relation between body-weight and the amount of 

 solid food consumed when' no restrictions were placed upon the diet 

 as regards quantity. 



I hope in future experiments to be able to reduce the errors intro- 

 duced by the work very considerably by the use of a work machine 

 so contrived that the external wOrk done can be measured fairly 

 accurately, and the internal work to some extent regulated. Absolute 

 results cannot, I think, be hoped for, but much may be done in the 

 way of rendering one experiment comparable with another, which at 

 present can hardly be said to be the case. 



I introduce here a series of experiments made in 1879, which, 

 though not made with such accuracy of method as the later series of 

 1882 and 1883, tend very materially to confirm' the' results then 

 obtained. 



Experiments o/1879. 



The nitrogen of the f eeces in these experiments was^ estimated by 

 mixing the whole quantity passed during each experiment, and 

 making one analysis in each case. The total quantity was as 

 follows :— 



Nitrogen. 

 18 -093 grams. 

 16 -083 , r 



15 -294 „ 



16 -872- 



Diet during the Experiments of 1-879. 



Food-stuff. 



Daily quantity. 



Nitrogen. 





grains. 







500 



9-485' 





50 



G'484 





60 



6-168 





100 



1-330 





300 



0-990 





3( 



o-ooo 





100 



000 





12 



0-400 





1422 



18-857 



Experiment I 



n 

 in 



