102 PHYSIOLOGY CHAP. 



detract from the scientific and practical value of the results 

 obtained by Chitteuden in his experiments on the other half, who 

 had the courage and strength of will to hold out to the end of 

 the test. 



Chittenden has proved that after a few days the organism 

 adapts itself and becomes accustomed to such a diet, if it be 

 persevered with, and above all, if the change be effected gradually 

 and not suddenly. Not only does the first feeling of emptiness 

 and weakness disappear, but the general sense of comfort becomes 

 more marked, the organism feels stronger and more inclined to 

 work, and there is an increased sense of well-being. We observed 

 and recorded something very similar with regard to the sensation 

 of hunger in the case of Succi during the first days of his pro- 

 longed fast at Florence. It is, therefore, according to Chittenden, 

 a mere prejudice to suppose that our physical and mental vigour 

 and our power of resisting disease are increased by a plentiful 

 diet of meat. Since purins, creatin, and uric acid, the inter- 

 mediate products of the metabolism of protein, are pre-eminently 

 toxic, it may, on the contrary, be argued that when an excessive 

 quantity of meat is taken daily, a large quantity of these products 

 circulates with the blood throughout the organism, with possible 

 harmful results, specially to the nerve centres. We may add 

 another important consideration : in order to digest all the protein 

 food-stuffs, to transform and render innocuous all the intermediate 

 products of their metabolism, and to eliminate, through the 

 kidneys, all the final products, urea, uric acid, creatin, etc., we are 

 forced to employ a great amount of glandular activity, partly to 

 the detriment of the function of the higher tissues of animal 

 life, such as the muscular and nervous. 



" It is quite evident," concludes Chittenden, " from a study 

 of the results obtained in the foregoing experiments that young, 

 vigorous men of the type under observation, trained in athletics, 

 accustomed to the doing of vigorous muscular work, can satisfy 

 all the true physiological needs of their bodies and maintain their 

 physical strength and vigour, as well as their capacity for mental 

 work, with an amount of proteid food equal to one-half, or one- 

 third, that ordinarily consumed by men of this stamp. As the 

 results show, all these men reduced their rate of proteid metabolism, 

 in-such degree that the amount of nitrogen excreted daily during 

 the period of the experiment averaged 8 '8 grams, implying a 

 metabolism of about 55 grams of proteid matter per day. 



" In other words, these athletes were able to reduce their 

 nitrogenous metabolism to as low a level as many of the men of 

 the professional group and of the soldier group, and this with not 

 only maintenance of health and strength, but with a decided 

 increase in their muscular power. 



" Metabolised nitrogen per kilo, of body-weight for all these 



