518 Sugar. [November, 



also formed during the germination of seeds and in the process of 

 fermentation. Cane sugar is distinguished from glucose by several 

 tests. It crystalizes in oblique four- sided prisms terminated by two- 

 sided summits ; grape sugar never truly crystalizes, although it 

 sometimes hardens into a concrete mass. Cane sugar is also much 

 the sweetest, nearly twice as sweet as the other, it also affects polar- 

 ized light differently, giving the colors in order when turned to the 

 right, while the other requires to be turned to the left. It is also 

 charred by the action of strong sulphuric acid, while the latter is 

 not. But the most accurate method of testing them is by means of 

 Bait of copper. A few drops of sulphate of copper and potash being 

 added to a solution of cane sugar, it remains some time a greenish 

 blue, but if the same be added to grape sugar it immediately changes 

 into a reddish yellow. 



The flavor of cane sugar, as it occurs in commerce, varies greatly, 

 according to the sources from whence it is derived, for it is mixed 

 with vegetable secretions; but when pure, is a clear white color and 

 of about the same taste, from whatever source it may be derived, but 

 it is very liable to change partially or wholly during its manufacture 

 into grape sugar, or at least into an uncrystalizable sweet, to the 

 great pecuniary loss of the manufacturer. If we make a solution 

 of the best crystaline article we shall find that it can be prevented 

 from recrystalizing, first by boiling a long time ; 2nd, by the addition 

 of an acid ; 3d, by the presence of an alkali ; 4th, by heating to 

 four hundred degrees. It is evident then that the sugar boiler must 

 exercise great care, if he wishes to obtain the greatest amount of 

 grained sugar from a given amount of juice. Science has come to 

 his aid. Noticing that water boils at a low temperature in a vacuum, 

 the vacum pan is constructed in which, without the least danger of 

 burning, the water is driven rapidly away. That no acid may re- 

 main, lime is added, which, unlike any other alkaline base, forms in- 

 soluble compounds, which of course can be easily removed from the 

 liquor, either by settling or straining ; that it be not added in excess, 

 blue test paper is put in the juice and the addition of lime ceases, 

 the instant the blue color is not longer changed to red. 



By a proper attention to these matters the yield is nearly doubled 

 over the old unscientific methods. But there is a vast field left for 

 discovery and improvement. It is to be hoped that a chemical treat- 

 ment will yet be discovered by which the whole of the sweet will 

 be crystalized and that all the starchy matter itself may yet be con- 



