33 



[Caiiauba Wax, the coating of the lea^-es of Copernicia cerifera. 

 It is yellow, harder than bees' wax, of 0*99907 specific gi-avitj 

 and 84° fusing point. Contains, according to N. Stony- Waskelyne, 

 amongst other ingredients, Melissin.] 



Caiie-Su«'ar (common sugar) = Ci2 Hn On. Diffused through- 

 ovit the vegetable kingdom, but especially in the stalks of Graminese, 

 in succulent roots (beet-roots for instance), in the sap of the stem 

 of several trees (maple, birch, lime, palm, walnut), in fruits 

 (always accomjDanied by other sorts of sugar), in seeds and flowers. 

 On a small scale it is obtained best by boiling the respective 

 vegetable substance, reduced to a proper state, with alcohol of 

 90%, filtering and keeping cold for rather a long time, to form in 

 crystals. It crystallises in large, pellucid klinorhombohedra, is the 

 hardest kind of sugar, of a pure sweet taste, has a density of 1'589 

 to 1"630, fiises at 160° without loss of weight to a clear, pale- 

 yellow liquid, turns brown above 180° under loss of weight, 

 acquires a bitter taste, swells up, becomes darker and is finally 

 reduced to coal; dissolves in one-third part cold, in any quantity 

 of hot water, little in strong alcohol, not in ether. The aqueous 

 solution is tolerably permanent in the cold, but is converted into 

 grape-sugar and fruit-sugar by continued boiling, or more readily 

 by heating with diluted (not oxydising) acids, but gives rise to 

 coloured humus-like products when treated so for a longer time; 

 it becomes black by concentrated sulphuric acid and yields with 

 nitric acid in the heat much oxalic, but no mucic acid. When 

 boiled with alkalies and alkaline earths, the cane-sugar does not 

 become perceptibly brown; its aqueous solution, mixed with car- 

 bonate of soda and boiled with subnitrate of bismxith, does not 

 colour the latter. Cane-siigar does not reduce the alkaline tai'tarate 

 of copper when boiled with it; ferments with yeast only after being 

 converted into grape-sugar; is not precipitated by acetate of lead 

 unless ammonia be added. 



Quantitative estiviation of Cane Stcgar. — Since its isolation in 

 the pure state is always connected mtli loss, methods have to be 

 applied which permit an estimation even in presence of other 

 matters; these are commonly, fermentation or treatment with an 

 alkaline solution of tartarate of copper. 



1. By fermentation with yeast. — The quantity of sugar may be 

 estimated either by the weight of the carbonic acid or of the 

 alcohol formed by this method. One hundred parts cane-siigar 

 were formerly supposed to yield after combining with 5-26 parts 

 water: 5 1*44 parts carbonic acid and 53-82 parts alcohol; but 

 according to Pasteur's direct estimations only 49 "12 parts carbonic 

 acid and 51*01 parts alcohol are formed, while the rest of the 

 sugar is used up in the formation of glycerin and of succinic 

 acid. This way of estimation can, of course, only be applied in 



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