Fisher — Tlie Effect of Diet on Endurance. 45 



Under flesh foods are included all meat- and " stock-" soups. It 

 has been shown that although these extracts of meat contain a large 

 amount of nitrogen, it is not in the form of proteid which can be 

 utilized, but only of waste nitrogen which must be excreted. Ap- 

 parently the sole virtue of such soups is that they supply the " pepto- 

 genic " stimulus above referred to. 



The experiment will be seen to harmonize with and supplement the 

 experiment of Professor Chittenden, on which it was founded ; but 

 the objects of the two experiments were quite different. Professor 

 Chittenden's was aimed to ascertain the physiological requirements 

 as to proteid, and did not touch upon the question of endurance. 

 Moreover, Professor Chittenden, in order the better to measure the 

 proteid and nitrogen, artificially reduced the quantities ingested, 

 whereas in the present experiment, test was made of Mr. Fletcher's 

 claim, that thorough mastication leads naturally to the adoption of 

 the physiological amount of proteid. This we found to be true, espe- 

 cially after the introduction, at the middle of the test, of the sugges- 

 tion that when appetite was in doubt, the lower proteid foods should 

 be selected. But the tendency was quite marked during the first 

 pei'iod also, and might have been expected to lead to the same results 

 without the introduction of even the suggestion of voluntary choice, 

 had the experiment been long enough. This was the experience of 

 others, notably Mr. Fletcher himself, whose case, in fact, first called 

 Professor Chittenden's attention to the possible virtues of low 

 proteid. 



The practical value of the experiment consists in the fact that any 

 layman can appl}- it, with or without a knowledge of food values, 

 though with more advantage if he possesses than if he lacks such 

 knowledge. 



If the dietetic rules of the present experiment are followed, no self- 

 denial as to foods is required. It is, however, absoluteh" necessary 

 that there should be self-control enough to break up the habit of 

 hurried eating to which modern civilization has brought us, habitu- 

 ating us, as it does, to eat against time. 



Experience indicates that appetite does not lead to a diet fixed in 

 amount or constituents, but moves in undulating waves or cycles. 

 The men who took part in the experiment were encouraged, after 

 any of the symptoms which seemed to be associated with high pro- 

 teid (such as heaviness, sleepiness, stiffness or soreness after exer- 

 cise, or catching cold), to cut down on their j^i'oteid and substitute 

 fat to restrain the gastric juice. This advice was intended to make 



