600 QRAMINEM 



is again Tolatilized by the beat, is of service, for tbe reason 

 stated. Subjected to dry distillation, sngar yields aldehyd, 

 acetone, acetic acid, tarry products, and carbonic acid, carbonic 

 oxide, and marsb gas. According to Lassaigne, iodine heated 

 with solution of sugar is conyerted into hydriodic acid. Under 

 the influence of ferments, as well as of dilute acids, cane-sugar 

 is converted into invert-sugar^ which is a mixture of dextrose or 

 grape-sugar and levulose or . fruit-sugar, and is directly 

 fermentable. This inversion of sugar takes place slowly on 

 boiling with water, but cold aqueous solutions keep unaltered 

 for a long time, provided the access of ferments suspended in 

 the air be prevented. Under the same condition, according to 

 the investigations of Kreusler, Lemoine, and others, light does 

 not exert the inverting effect reported by Raoul { 1871)» 

 Nitric acid inverts cane-sugar, readily, and when heated 

 with it produces saccharic, racemic, tartaric, and oxalic 

 acids. 



Tests. — The purity of cane-sugar is ascertained by the 



physical properties described above and by its complete 



solubility in water and alcohol. The absence of glucose or 



^roil ^ -v...iv. v/o. i,xx^ x^.*^ - 



below. "Aqueous and alcoholic solutions o£ sugar should 

 have no effect on litmus-paper. The solution in 20 parts of 

 distilled water should be scarcely rendered turbid by silver 

 nitrate or barium nitrate (chloride and sulphate)." Neither 

 an aqueous nor an alcoholic solution of sugar kept in large, 

 well- closed, and completely. filled bottles should deposit a 

 sediment on prolonged standing (absence of insoluble salts, 

 foreign matters, ultramarine, Prussian blue, &c.). If a portion 

 of about 1 Gm. of sugar* be dissolved in 10 cm. of boiling 

 water, then mixed with 4 or 5 drops of test solution of nitrate 

 of silver and about 2 cm. of water of ammonia, and quickly 

 heated until the liquid begins to boil, not more than a slight 

 coloration, but no black precipitate should appear in the liquid 

 after standing at rest for 5 minutes (absence of grape-sugar 



and of more than a slight amount of inverted sugar), {^^^^^ 

 and JIaisch.) 



