in its action on polarized light. Dextrose rotates the plane 

 of polarized light to the right hand and laevulose to the left 

 hand. Dextrose and laevulose are not so readily crystallized 

 as cane-sugar is, and the molasses of cane-sugar and other 

 raw sugars contain dextrose and laevulose. These Glucoses 

 being hygroscopic substances absorb moisture from damp air, 

 which accounts for gur and dalua sugar running in the rainy 

 season and good Cossipore Factory sugar remaining dry. 

 Impurities in the form of Glucoses and ash constituents pre- 

 vent crystallization of cane-sugar more or less. One part of 

 glucose prevents i part of cane-sugar from crystallizing and 

 one part of ash prevents 5 parts of cane-sugar from crystal- 

 lizing. Unripe cane, maize-stalks and sorghum-stalks contain 

 less cane-sugar and more glucose. A properly ripe cane 

 contains about 80 per cent, of water, 16 per cent, of cane- 

 sugar, '3 per cent, of glucose, '75 per cent, of ash, and about 

 3 per cent, of albuminoid matter. 



587. Beume's Saccharometer is graduated to indicate the 

 amount of sugar in a saccharine solution, each degree on the 

 scale representing 0*019 per cent, of sugar, so that a liquor 

 registering 10 would contain 1-9 per cent, of sugar. Syrups 

 when hot are about 3 degrees lighter than when cold and the 

 Saccharometer is standardised at 84 F. In clarifying and 

 in boiling sugar-cane juice the use of a copper-case thermo- 

 meter is essential. One registering from o to 300 F. is 

 the best to use. 



588. Dilute acids convert cane-sugar into a mixture of 

 dextrose and laevulose. Cane-sugar rotates the plane of 

 polarized light to the right and a mixture of equal parts and 

 dextrose and laevulose to the left. Sugar is therefore said 

 to be 'inverted' by dilute acids. Sugar-cane juice is naturally 

 somewhat acid and hence in the boiling process some cane- 

 sugar is inverted into glucose. The only dilute acid which 

 does not ^invert the sugar liquid is Phosphoric acid ; hence 

 this acid is used along with milk of lime in clarifying the 



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