474 PHYSIOLOGY. 



Sondeu and Tigerstedt show that there is a greater combustion 

 due to the age of the child, the younger the child the greater the excess 

 of combustion. The male child excretes more C0 2 than the female of 

 same age and weight, due to the greater activity and tonus of the 

 muscles. 



Luxus Consumption. 



In Liebig's old theory, the fats and carbohydrates were supposed 

 to generate heat, whilst the proteids were muscle-builders, and the life 

 phenomena were supposed to be due to chemical changes in the proteid. 

 When it was found out that proteids in part also generated heat, it 

 was looked upon as a wasteful use of good material, and was denomi- 

 nated a luxus consumption. 



The luxus consumption theory of Voit is that the excess of 

 proteids in the blood and lymph is oxidized in those fluids. Hence we 

 see there can be a dividing line made between the circulating proteid 

 of the blood and the lymph and the organ proteid of the cells. 



Unorganized and organized proteid are better terms than cir. 

 culating and tissue proteid of Voit. The tissue proteid or stable pro- 

 teid is hard to disintegrate. 



It is now believed, according to Abderhalden, that the amido 

 acids are the circulating or unorganized proteid of Voit. 



INTERMEDIATE METABOLISM. 



According to Pasteur, all oxidations are accomplished by intra 

 cellular ferments of the cells of the tissues, which are denominated 

 oxidases. The act of autolysis proves that intracellular ferments 

 exist. 



The act of autolysis or digestion outside the body under antiseptic 

 precautions produces with the proteids all the products found when 

 digestion takes place in the intestine. Here the intracellular enzymes 

 are the active agents. 



All the tissues of the body have a large number of enzymes 

 capable of producing a great variety of metabolic products. The 

 intracellular ferments are the controlling factor by which the needs 

 of the body are supplied with metabolic products. 



Every species of animal has its own specific proteid as the 

 precipitin test shows. The caseins of different kinds of milk when 

 injected into the circulation also produce specific precipitins by means 

 of which these caseins can be differentiated from one another. No 

 matter what kind of food of a proteid nature is taken into the intestine, 



