DISCHARGE OF NITROGEN. 35 



grammes daily, of which 560 grammes are discharged as CO 2 , about 9 

 grammes in urea, 97 grammes in H 2 O, of which last 78 grammes are 

 formed at the expense of the hydrogen of the fat. Hence the quotient 

 -^-=o 84. In inanition, when (as in the case represented in Table II. 

 the proteids and fat of the organism take the place of food, and the CO, 

 discharge is reduced to 660 grammes daily, the assumption of O required is 

 649 grammes, of which 480 grammes are discharged in CO 2 , 4'5 in urea, and 

 164*5 in H 2 O ; of this last 156 grammes are due to the oxidation of fat. 



In the state of hibernation the respiratory quotient is 

 smaller than in any other known condition (often less than 

 0*5), for the hibernating animal lives almost entirely on 

 its own fat. In the similar state of inanition the excess 

 of the oxygen absorption is not so great, for here the 

 proteid constituents of the tissues waste in much larger 

 proportion. 



The " insensible loss " is increased by muscular work ; 

 for, although the quantity of O absorbed is large during 

 exertion, this is far more than counterbalanced by the 

 greater increase of the CO 2 discharge (diminution of the 

 respiratory quotient), and the still greater augmentation 

 of the evaporation of water from the pulmonary and cuta- 

 neous surfaces. 



Diminution of the bodily temperature, however pro- 

 duced, determines increased CO 2 discharge. In small 

 animals the CO 2 discharge is greater in proportion to the 

 body-weight than in large ones. 



The Discharge of Nitrogen. 



The whole of the nitrogen which enters the circulating 

 blood by intestinal absorption (with the exception of so 

 much of the N of the faeces as is derived from unabsorbed 

 secretions) is discharged by the urine. The rate of dis- 

 charge is observed to vary according to the rate at which 

 nitrogen has been absorbed during the previous period, so 

 that under normal conditions the processes balance each 

 other. But in order to the establishment of this state of 



D 2. 



