EXCHANGE OF MATERIAL. 447 



part of the starvation period. The heat of the animal sinks only a 

 few days before death, and at about 33 to 30 C. death results. 



If the carbon is burnt with oxygen into carbon dioxide, the 

 carbon dioxide produced occupies the same volume as the oxygen 



OO 



consumed, and the quotient ^ is therefore 1. The same is true 



of the burning of the carbohydrates, which contain in themselves 

 the necessary quantity of oxygen to oxidize the hydrogen, and only 

 the quantity of oxygen required to oxidize the carbon is necessary 

 to be taken up for the burning of the carbohydrates into C0 2 and 

 H 2 0. In the burning of fats and proteids this is different. In 

 these cases an absorption of oxygen is necessary not only for the 

 burning of the carbon but also for the hydrogen, and the volume of 

 the carbon dioxide formed is therefore smaller than the oxygen 



PO 

 consumed. The quotient ~-^ must therefore in these cases be 



smaller than 1. The conditions are still more complicated for the 

 proteids, because these bodies contain sulphur which is oxidised 

 into sulphuric acid, and also because they are not completely burnt 

 in the organism, but yield nitrogenized decomposition products 

 which contain hydrogen and oxygen as well as carbon. 



From the above it follows that in man, on a mixed diet, the 

 proportion between the inhaled oxygen and the expired carbon 

 dioxide, or the so-called respiratory quotient, must be smaller than 1 . 

 As a rule, it is 0.73-0.86 on a mixed diet. On feeding with an 

 exclusively vegetable food rich in carbohydrates it is closer to 1 ; 

 with a strictly meat diet it is lowest, about 0.7. In starvation, when 

 the person or animal lives entirely upon his own body, it must be 

 about the same as when fed entirely upon meat and fat. As the 

 quotient for the burning of proteids is 0.81-0.75, and for the 

 burning of fats 0.7, the respiratory quotient in starvation must be 

 in the neighborhood of 0.7. In the above-mentioned starvation 

 experiments made by C. SCHMIDT on a cat it was 0.765, while in his 

 observations on CETTI it was still lower, or 0.68-0.65. 



Water passes uninterruptedly from the body in starvation even 

 when none is given. If the amount of water in the tissues rich in 

 proteids is considered as 70-80$, and the amount of proteids in 

 the same 20$, then for each gramme of destroyed proteids about 



