DESTINATION OP NON-AZOTIZED ALIMENTS. 151 



155. Now, in regard to the non-azotized, or the saccharine 

 and oleaginous groups of alimentary substances, it appears to 

 be an established fact, that none of the higher animals can be 

 permanently supported upon them alone. Thus, dogs that 

 have been fed on sugar and starch only, do not survive long ; 

 and it is evident, before their death, that their tissues are 

 gradually undergoing decay. It has been thought that such 

 results might be partly explained upon the fact, that animals 

 fed upon one simple substance soon become disgusted with it, 

 and will even refuse it altogether ; but the experiments have 

 been repeated with a combination of various non-azotized sub- 

 stances, and the same result has occurred. Still it is too much 

 to affirm, as some have done, that these substances do not con- 

 tribute in any degree to the nutrition of the animal tissues; 

 since there is ample evidence that the presence of fatty matter in 

 the blood is a condition essential to the production of newly 

 forming tissue ; and we find that either oleaginous substances, 

 or substances belonging to the saccharine group which can be 

 readily converted into fat within the body, constitute an im- 

 portant part of the food of Man, and of animals generally. 1 



156. That such a conversion can take place, has been de- 

 monstrated by experiments carefully conducted upon bees, 

 which have been found to generate wax when fed upon sugar 

 only and also upon cows, which give off in their milk so 

 much larger a quantity of butter than can be produced at the 

 expense of the fat contained in their food, that there is no 

 other mode of accounting for its presence, than by regarding 

 it as generated from the starchy portion of their diet. And 

 the fattening power of starchy and saccharine articles of diet 

 is well known to breeders of cattle ; though the articles which 

 contain oily matter in addition seem to possess a higher value 

 in this respect. 



157. But if these non-azotized compounds, which exist so 

 largely in the food of herbivorous animals, are not destined 

 to form any other permanent part of the animal organism 

 than the oleaginous contents of the fat-cells ( 46), the ques- 

 tion again arises, what becomes of them ? It is not enough 



1 The value of cod-liver oil, which is now so extensively used in the 

 treatment of diseases of imperfect nutrition, seems to depend upon the 

 readiness with which it can be digested and assimilated, so as to furnish 

 the supply of fat required by the formative processes. 



