314 PHYSIOLOGY AT THE FARM. 



juices are the sole support of such animals, then, doubtless, a 

 sufficient proportion of proteine compounds or flesh-formers 

 are present along with the sugar in such juices. It has long- 

 been a received belief, nor is there any reason to doubt its 

 authenticity, that during the sugar season of the West India 

 Islands "every negro on the plantations, and every animal, 

 even the dogs, grow fat." Fat is a non-azotised substance, so 

 that there is no difficulty in believing that the use of sugar, 

 along with other suitable substances, may fatten animals ; and as 

 pure sugar is not referred to in the statement made, but the 

 juice of the sugar-cane, in which, doubtless, there is flesh- 

 forming material, it is possible that the fattening spoken of 

 may take place for a time, even when nothing but cane-juice 

 is supplied as nourishment. It is alleged that the fattening 

 tendency of sugar is not greater than that of a corresponding- 

 weight of starch. Hence if it be the fact that both sugar and 

 starch have a manifest fattening tendency, the name respira- 

 tory aliments does not so strictly apply to them as the mere 

 negative term non-azotised aliments. 



By long boiling, a solution of sugar acquires an acid reac- 

 tion, while it irrecoverably loses the property of crystallising. 

 During this change an additional quantity of the elements of 

 water is assimilated, so that the composition of the substance 

 no longer bears to be 12 atems carbon and 11 atoms water, 

 but 12 atoms carbon and 12 atoms water. This substance is 

 named inverted sugar, for a reason to be afterwards mentioned, 

 and is the same as what has been called fructose, or the sugar 

 of fruit. If the boiling is carried still farther, particu- 

 larly after the addition of an acid, such as the oxalic, citric, 

 malic, or any of the stronger acids, another proportion of 

 water is assimilated, and the inverted sugar is transformed into 

 grape-sugar, which consists of 12 atoms carbon and 14 atoms 

 water. In this last case there is produced at the same time a 



