256 HALOIDS AND HALOID BASES. 



Edwards,* found reason to believe that bees cannot be fed for any 

 length of time on pure cane-sugar ; but that when fed upon the 

 honey yielded by this sugar, which contains a very little wax, they 

 were able to produce that substance. Boussingault,t Persoz,i and 

 others, have since that period convinced themselves, by repeated 

 experiments on pigs, ducks, and cows, of the correctness of Liebig's 

 view, and therefore this long-contested question may now be 

 regarded as at rest. 



But it must not be forgotten that these experiments have only 

 been conducted on the statistical method (that is to say, by a com- 

 parison of the quantity discharged and the quantity taken up by 

 the organism) ; and that they cannot therefore afford more than 

 the general demonstration that under many relations, fat must be 

 formed within the animal body. But the following questions still 

 remain unanswered : Does the animal body continue to exercise 

 its property of generating fat, when a sufficient supply has been 

 conveyed to it by food ? What is the true seat of the formation 

 of fat ? And finally, how, and by what process, and in what che- 

 mical proportion, is fat formed from starch or nitrogenous 

 substances ? 



The first question, as to whether the organism constantly exer- 

 cises its power of forming fat, does not admit of a solution in the 

 present state of our knowledge, nor until a satisfactory answer 

 can be given to the two other questions. If Boussingault's view 

 be correct, that the ordinary vegetable substances contain suffi- 

 cient fat to compensate for what has been lost through the func- 

 tions of the animal body, we might infer that fat would only be 

 generated from other substances when the food is deficient in fatty 

 matters, or when the supply of fatty food is inadequate. It may, 

 however, be argued against this teleological view, that if the con- 

 ditions for the formation of fat are once present in the animal 

 organism, this process will probably continue in operation without 

 reference to the plus or minus supply of fat. But many patholo- 

 gical phenomena appear to show that this process may in some 

 cases be abnormally excessive. 



According to the views of Liebig and Scherer, in which most 

 observers now concur, the seat of the formation of fat is to be 

 sought in the prima vice. This hypothesis is not, however, based 

 on strict proof, and its value greatly depends upon the origin we 



* Ann. de Chim. et de Phys. 3 Ser. T. 14, p. 400. 

 t Compt. rend. T. 20, p. 1720. 

 J Ibid. T. 21, p. 20. 



