56 THE CARBOHYDRATES. 



(3) CH 3 (OH).CH(OH).CH.(OH).CH(OH).C.CH.N.NH.C 6 H 6 +2H a O+2HCl = 



N.NH.C 6 H.. 



2NHa.NH.CeH5.HCl + CH 2 (OH).CH(OH).CH(OH).CH(OH).CO.COH. 



Oson. 



(4J CH 3 (OH).CH(OH).CH(OH).CH.(OH).CO.CHO -f 2H= 



CH 2 (OH).[CH(OH)] 3 .COCH 2 (OH) 



Lsevulose. 



. The same result may be reached when the corresponding osazon 

 of the aldose is directly reduced, and the resulting osamin is treated 

 with nitrous acid. The glucosamin thus obtained as an intermediary 

 product is of special interest in so far as it also results from the de- 

 composition of the hyalins chitin and chondroitin. By oxidation with 

 bromine glucosamin then yields chitonic acid, from which the cor- 

 responding sugar, chitose, can be obtained on reduction. The 

 changes which are here involved may be represented by the equa- 

 tions : 



(1) CH 2 (OH).CH(OH).CH(OH).CH(OH).C.CH.N.NH.C 6 H 5 + H 2 O + 4H ^ 



Phenylglucosazon 



N.NH.C 6 H 5 

 CH 2 (OH).CH(OH).CH(OH).CH(OH).CO.CH 2 (NHo) + 



Glucosamin C 6 H 6 .NH,.NH -f C 6 H 6 .NH 2 



Phenylhydrazin anilin 



(2) CH 2 (OH).CH(OH).CH.(OH.)CH(OH).CO.CH 2 (NH 2 ) + HNO 2 = 



Glucosamin 

 H 2 0+ 2N + CH 2 (OH).CH(OH).CH(OH).CH(OH).CO.CH 2 (OH) 



Lsevulose. 



(1) C 18 H 30 N 2 O 12 + 4H 2 O = 2CH 2 (OH).CH(OH).CH(OH).CH(OH). 



Chitin. Glucosamin. CO.CH 2 (NH 2 ) + 3CH 3 .COOH 



(2) CH 2 (OH).CH(OH).CH(OH.)CH(OH).CO.CH;(NH 2 ) + 4O = 



CH 2 (OH).CH(OH).CH(OH).CH.(OH).CH(OH).COOH -f HNO 2 

 Chitonic acid 



(3) CH 2 (OH).CH(OH).CH(OH).CH(OH).CH(OH).COOH -f 2H = 



CH 2 (OH).[CH(OH)] 4 .COH + H 2 O 



Chitose 



On boiling with dilute mineral acids the hexoses are decomposed 

 into formic acid, Isevulinic acid, and certain humin substances. With 

 the alkalies, on the other hand, they yield, besides other products, 

 also Isevulinic acid and a ketonic acid of the composition CH 3 .CO. 

 CH 2 .CH 2 .COOH. On the application of dry heat they form so- 

 called caramel, and are finally carbonized. 



As .stated above, most of the hexoses are capable of undergoing 

 fermentation i. e., a decomposition which is effected through the 

 activity of certain minute organisms. According to the character 

 of the specific organism present, we distinguish between alcoholic 

 and acid fermentation, such as lactic acid, butyric acid, and acetic 

 acid fermentation. The former is brought about through the influ- 

 ence of various varieties of yeast, while the latter are referable to the 

 activity of certain bacteria, such as the Bacterium lactis aerogenes, 

 the Bacillus acidi butyrici, the Mycoderma aceti, etc. The decom- 



