METABOLISM. 485 



of the sweat glands his temperature rapidly rose to 40-41 degrees G. 

 when he did heavy manual labor or after he sat for some time in the 

 rays of a summer sun. 



When the body is in nitrogenous equilibrium and more water is 

 drunk, then the nitrogen in the urine increases if there is diuresis, 

 because the tissues are more thoroughly washed out. In thirst the 

 consumption of oxygen is not increased; hence the diminution of 

 water does not have any effect on fat in obesity. Thirst increases the 

 excretion of nitrogen. 



Mineral Substances. 



There is neither any liquid nor any tissue which does not produce 

 an ash upon calcination. The inorganic salts are either in solution or 

 combined with organic substances, notably proteid. The combination 

 of the various needful salts with protoplasm, the substratum of life, is 

 of the highest importance. 



Forster, of Strassburg, is of the opinion that certain combustible 

 compounds of foodstuffs and the body tissues, with regard to which 

 there is as yet little exact knowledge, play an important part in 

 nutrition. Pigeons could be kept alive when fed exclusively on wheat, 

 but if the wheat were extracted with dilute acids the pigeons died in 

 from three to four weeks. If the substances thus extracted were added 

 to the treated wheat, death still occurred. This proved that the 

 elementary ash must be combined with the cell in order to be utilized. 1 



The nature and quantity of mineral substances demanded by the 

 growth of the child is clearly indicated in the composition of milk. 

 The human body loses about 25 grammes of mineral substances a day, 

 of which one-half is sodium chloride, the other half potassium sulphate 

 and phosphate; also sodium phosphate and sulphate, lime, magnesia 

 and a small quantity of iron. The mineral salts also have a function. 

 The salts of soda favor a solution of the proteid substances in the 

 blood. Iron is indispensable ; lime is necessary for the coagulation of 

 the blood, milk and myosin. The ions of lime and potash and soda 

 combined in Binger's solution maintain the functional activity of the 

 heart and contractile tissues. The salts of lime modify the irritability 

 of the central nervous system. The iodine in the thyroid gland is 

 intimately concerned in nutrition. 



Potassium and Sodium. Potassium is found in all the vegetable 

 and animal cells. Sodium is found especially in the blood plasma 

 and in the liquids of the organism. These two basic bodies are indis- 



1 British Mod. Jour., p. 1077, 1907. 



