METABOLISM 165 



is oxidized, so that the oxygen consumption is decreased at 

 most by 20-25$. Hence the respiratory quotient during the 

 first days of fasting is rapidly decreased, but after this 

 remains quite constant till a few days before death. The 

 more body fat there is present, the smaller the value of this 

 constant respiratory quotient. In animals well provided 

 with fat, the respiratory quotient has a value which it ought 

 to have when pure fats are oxidized. A few days before 

 death by starvation the respiratory quotient is increased 

 because of the increased proteid consumption. 



The amount of proteid consumed (the nitrogen excretion) 

 decreases very rapidly to less than one-half and then remains 

 constant for a few days till a little while before death, when 

 it becomes larger than it was before starvation. The course 

 of proteid consumption during starvation depends upon the 

 amount of non-nitrogenous material for combustion stored 

 up in the body. Of this material the fats only are of impor- 

 tance, since the carbohydrates (glycogen) are already used 

 up in the first days of starvation. The longer the supply of 

 fat lasts, the longer it takes before the excretion of nitrogen 

 is increased. 



That the excretion of nitrogen reaches its minimum during 

 the first days of starvation, that it then remains constant for 

 some time, and at last again increases, is evidently due to 

 the fact that, at first, less proteids are used in the process of 

 combustion than fats, and during the latter part more. 



The amount of material lost is not the same for all organs. 

 The organs and tissues suffering most are the adipose tissue, 

 the muscles, and the abdominal glands; the heart, brain, 

 and muscles of respiration suffer less. During inanition the 

 body loses continually in weight, this loss being greatest 

 during the first days. Of this loss, two thirds is due to loss 

 in water, one third to loss in body proteid and fat. The 

 amount of fat lost is from two to four times that of the pro- 

 teids lost. 



The time when death occurs is therefore dependent upon 

 the condition of the body nutrition at the beginning of star- 



