118 PHYSIOLOGY OF THE DOMESTIC ANIMALS. 



or malt, is termed alcoholic fermentation, and is accompanied by the 

 development of carbon dioxide, with small amounts of glycerin and 

 formic acid. The fermentation caused by the lactic acid ferment, or 

 decomposing nitrogenous matter, results in the final development of 

 butyric acid. 



Various tests have been proposed for the qualitative and quantitative 

 estimation of grape-sugar. Of these it maj 7 be mentioned that in 

 solutions of cupric hydrate in the presence of free alkalies, when subjected 

 to boiling, grape-sugar reduces the cupric oxide into red or j'ellow 

 anhydrous cuprous oxide (Trommer's and Fehling's test). Basic nitrate 

 of bismuth is reduced by grape-sugar to bismuth oxide (Bottger's test). 

 When boiled with half its volume of liquor potassse grape-sugar solutions 

 acquire a bright-brown color, due to the formation of melassic acid. If 

 nitric acid is now added, the odor of formic acid is evolved (Moore's 

 test). For the methods of quantitative estimation of sugar solutions 

 and further details as to testing for sugar, references must be made to 

 text-books on physiological chemistry. 



2. Lsevulose. — As with dextrose and cane-sugar, lajvulose is also 

 abundantly distributed through the vegetable kingdom, especially in the 

 acid fruits. It forms a colorless, non-crystallizable syrup, with almost 

 as much sweetness as cane-sugar. It derives its name from its property 

 of rotating the plane of polarized light strongly to the left (at 15° C.= 

 — 10i;°). It is as powerful a reducing agent as grape-sugar. When 

 placed in contact with malt it undergoes alcoholic fermentation without 

 first being converted into dextrose. La-vulose is also formed in what is 

 termed the inversion of cane-sugar. When cane-sugar is subjected to 

 the action of dilute mineral acids, or the intestinal juices of animals, it 

 is turned into the so-called inverted sugar, which may be regarded as a 

 mixture of equal portions of dextrose and loevulose. 



3. Inosite (C 6 H 12 6 + 2II 2 0). — Inosite is a saccharine body which 

 is found in the heart-muscle and in most of the organs of the body, 

 especially of the horse and ox. It is also found in certain plants, es- 

 pecially in the unripe fruit of the Papilionaceee. Inosite crystallizes in 

 long, colorless, efflorescent tables, and in cabbage-like aggregations, 

 which when dried break down into a white mass! It has" a sweetish 

 taste, is easily soluble in water, but insoluble in alcohol and ether. Its 

 solutions are optically inactive. It does not reduce the copper test for 

 sugar. It is incapable of undergoing alcoholic fermentation, and is not 

 decomposed by caustic alkalies or weak acids. It is precipitated from 

 its solutions by lead acetate and ammonia. If inosite is evaporated 

 almost to dryness on a strip of platinum-foil with nitric acid, and the 

 residue moistened with a little ammonia and calcium chloride solution, 

 and again evaporated, a beautiful red coloration is produced (Scherer's 



