This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
As a result of examining a number of commercial samples of sugar of different grades, every one showed a glucose reaction. Some contained it in sufficient quantity to result in fermenting as soon as made into solution, while other samples contained it in such small quantity that they should not be considered adulterated products; but the presence of glucose is due to the process of refining, which always inverts some of the cane-sugar, and owing to some deficiency is not excluded from all varieties, but traces of different amounts are left behind. For testing sugars for saccharine, see "Saccharine".
Other Sugars: Glucose, Grape-Sugar, Dextrose or Starch-Sugar, C6H12O8; molecular weight 180. Hydrated, C6H3O6H3O; mol. weight 198. - "Carbohydrates having a sweet taste are frequently met with in plants and among the products of decomposition of those organic compounds forming the large class of glucosides. The sugar yielded by the latter is frequently though not always identical with the sugar met with in grapes and other fruits, and with that produced from starch. This is now very largely made for uses in the arts by boiling 100 parts of starch, 400 parts of water, and 4 or 5 parts of sulphuric acid, until starch can no longer be detected in the liquid, the transformation being hastened by heating under pressure; the free acid is then neutralized with chalk, the filtrate clarified and decolorized, if necessary, by treating it with clay and animal charcoal, and, finally, concentrated, preferably in a vacuum pan. The grape-sugar or glucose of commerce is prepared in this manner. Liquid glucose contains from 34 to 43 per cent, of dex. trose, from 0 to 19 per cent, of maltose, from 30 to 45 per cent, of dex trine, and from 14 to 23 per cent, of water. Solid grape-sugar is usually in a white or whitish irregularly granular powder or mass; from alcohol it may be obtained in compact, nodular groups of needles. A. Behi (1882) has shown that the cooling concentrated solution of glucose, on the addition of crystals or powdered crystals of that compound, will give a large crop of prism of anhydrous glucose. It rotates polarized light to the right, though less than cane-sugar, reduces the so-called noble metals and acquires a dark color when heated with solution of alkalies. It is less sweet than cane-sugar, is directly fermentable, undergoes by heat.alterations analogous to those of cane-sugar, is insoluble in ether dissolves in about 50 parts of alcohol, and requires little more than 1 par of cold water for solution; but after it has been rendered amorphous b: heat, it dissolves in water in nearly all proportions. Nitric acid oxidize it to saccharic, tartaric, racemic, and oxalic acids. Saccharic acid, H C6H8O8, is amorhous, deliquescent, freely soluble in water and alcohol and yields mostly crystallizable salts". - N. D.