NON-AZOTISED VEGETABLE PROXIMATE PRINCIPLES. 



93 



as it is found combined in the juice of the grape. As 

 caseine cannot be separated from its solutions by heat 

 alone, it is evident that when this agent is the only one to 

 the action of which cane-juice has been submitted, the 

 caseine must still remain dissolved in its original quantity. 

 Syrups prepared from cane-juice thus treated, undergo a 

 partial crystallization only, and are very much disposed to 

 run into one or more of the varieties of fermentation just 

 alluded to. Boiled cane-juice likewise changes its chem- 

 ical character with great rapidity, the three varieties of 

 fermentation taking place in it simultaneously. But while 

 the viscous and lactic acid fermentations predominated, as 

 we have seen, in the juice which has not been exposed to 

 heat, this viscous fermentation is the one which is the most 

 active. Caseine is, as has been already stated, insoluble in 

 pure water, but when the water has been acidulated by the 

 addition of any of the vegetable acids or acid salts, or when 

 it is rendered alkaline by a small quantity of potash, soda, 

 or hme, it becomes, in both cases, a solvent of this prin- 

 ciple. In the one it is separated from its solution by the 

 addition of an acid ; in the other by that of an alkali, 

 provided neither be in excess, otherwise it is first precipi- 

 tated, and afterwards re-dissolved. Vie can thus explain 

 the necessity for the employment of lime in the defecation 

 or clarification of cane-juice.^ 



The non-azotised vegetable proximate principles, except 

 cane-sugar, exist in a very small quantity in the fresh 

 juice, but rapidly increase at the expense of the sugar 



