'7 2 HUMAN PHYSIOLOGY 



found in the body is added to the food, we find this fat 

 deposited in the body. 



(fr) The carbohydrates of the food from which by reduc- 

 tion and synthesis fat is formed. By a diet rich in carbo- 

 hydrates glycogen and fat are deposited in the body. 

 Consequently the respiratory quotient may be greater than 

 one; i.e. carbohydrates must have been reduced and changed 

 to fats in the body. By this process oxygen would be set 

 free, which could then be utilized, in connection with the 

 inhaled' oxygen, in the formation of carbon dioxide. 



(c) It has been supposed that fats can be formed from 

 proteids, but no sufficient proofs have been furnished. 



For the purpose of laying up fat the best diet consists of 

 a moderate amount of proteicl and an abundant supply of fat 

 and carbohydrate. 



3. TJic effect of water and salts. Increase of water taken 

 up does not change the amount of metabolism, but during 

 the first day the excretion of nitrogen is increased, due to 

 a better washing away of the nitrogenous end-products of 

 metabolism. 



Neither does increase in sodium chloride produce any 

 changes in the extent of metabolism. 



4. Effects of spices. Alcohol does not change the meta- 

 bolism. Alcohol, like the other non-nitrogenous foodstuffs, 

 is completely oxidized soon after being taken into the body 

 and can therefore replace fats and carbohydrates. But, as 

 alcohol is a strong nerve poison, it cannot be regarded as a 

 valuable material for metabolism. 



Concerning the effects of spices upon metabolism, authors 

 differ widely. 



5. Effects of oxygen. Voluntary increase or decrease in 

 the amount of respiration has no effect upon metabolism, for 

 the taking up of oxygen and the giving off of carbon dioxide 

 is not altered by increased or decreased ventilation during 

 a few minutes. The increased activity of the muscles of 

 respiration may, of course, influence metabolism. Diminu- 

 tion in the amount of haemoglobin in the blood, by loss of 



