THE METABOLISM OP THE BODY. 437 



curacy, so that the results must he regarded as only approxi- 

 mately correct. It is, however, we think, hetter to examine 

 such statistical tables of analyses, etc., than to rely on the mere 

 verbal statement of certain results, as it leaves more room for 

 individual judgment and the assimilation of such ideas as they 

 may suggest outside of the subject in hand. 



The subject of diet is a very large one ; but it will be evi- 

 dent on reflection that, before an average diet can be prescribed 

 on any scientific grounds, the composition of the body and the 

 nature of those processes on which nutrition generally depends 

 must be known. Not a little may be learned by an examina- 

 tion of the behavior of the body in the absence of all diet, 

 when it may be said to feed on itself, one tissue supplying] 

 another. All starving animals are in the nature of the case/' 

 carnivorous. '' 



For the cat an analysis has yielded the following : 



Muscle and tendons 45'0 per cent. 



Bones 147 



Skin 12-0 



Mfesentery and adipose tissue 3 "8 " 



Liver 4-8 



Blood (escaping at death) 6'0 



Other organs and tissues 137 " 



The large proportional weight of the muscles, the similarly 

 large amount of- blood they receive, which is striking in the 

 case of the liver, also suggest that the metabolism of these 

 structures is very active, and we should expect that they 

 would lose greatly during a starvation period. It is a matter of 

 common observation that animals do lose weight and grow 

 thin imder such circumstances, which means that they must 

 lose in the muscles and the adipose tissue. Attempts have been 

 made to determine exactly the extent to which the various 

 tissues do suffer during complete abstinence from food, and 

 this may be gathered from the table given below. 



It will not be forgotten that about three fourths of the body 

 is made up of water, so that the loss of a large amount of the 

 latter during starvation is to be expected. 



In the case of a cat during a starvation period of thirteen 

 days 734 grammes of solids were lost, of which 248 grammes 

 were fat and 118 muscle — i. e., about one half of the total loss 

 was referable to these two tissues alone. ■ 



The other tissues lost as follows, estimated as dry solids : 



