120 Messrs Morrell and Crofts, Modes of Formation of Osones. 



glucosone, which reacts with phenylhydrazine at the ordinary 

 temperature to give glucosazone. 



Galactose, on oxidation, has not as yet yielded the corre- 

 sponding osone, and the investigation of the products is still being 

 carried on. Of the pentose group of carbohydrates, arabinose and 

 methyl pentose (rhamnose) have been investigated. Arabinose 

 yields very readily an osone, which reacts with methyl phenyl- 

 hydrazine at the ordinary temperature, giving an osazone identical 

 with that obtained by Neuberg from the oxidation product of 

 arabitol [Z. Ver. Rubenzucker Ind. 1902, 237]. 



Rhamnose, on oxidation with hydrogen peroxide in the presence 

 of ferrous sulphate, yields an osone. The osone has the same 

 properties as that prepared from rhamnosazone by the second 

 method described in the paper. 



Saccharose, when oxidised by neutralised hydrogen peroxide 

 in the presence of ferrous salt, is, at first, apparently hydrolysed to 

 glucose and fructose, which on oxidation yield glucosone [Morrell 

 and Crofts, J.G.8. lxxvii. 1219]. The disaccharides seem to react 

 with the oxidising agent in dilute solution more slowly than the 

 hexoses or pentoses. Maltose and lactose are, in comparison, only 

 slightly acted on to give substances of an osone nature. In all 

 these cases of oxidation ferrous sulphate seems to play the part 

 of a peroxydase. It is possible that the oxydase in the root of 

 the horse radish contains a substance with the properties of an 

 aldehyde [Bach and Chodat, Ber. xxxvi. 603] which acts as an 

 autoxydiser like benzaldehyde [P. Engler and Wild, Ber. xxx. 

 1669] to give a peroxide, which, in the presence of the peroxydase, 

 furnishes active oxygen. 



The oxidation of carbohydrates in plants to give substances of 

 an osone nature is not highly improbable. If saccharose is sup- 

 posed to be the first sugar formed by assimilation in plants [Horace 

 Brown and Morris, J.C.8. 1893, 604], this sugar might be slowly 

 acted on by the oxydases and peroxydases, being first inverted 

 and then partially oxidised to an osone. We have noticed that 

 fructose is more easily acted on by these oxidising agents, and the 

 part played by the ferrous sulphate as peroxydiser is easy to follow 

 in the oxidation of fructose by hydrogen peroxide. Oxidising 

 agents such as bromine and nitric acid do not seem to act on 

 fructose more rapidly than on glucose, and the stronger action 

 of hydrogen peroxide on fructose is very peculiar. When once 

 an osone is formed, it is able to react with any substance of a 

 basic nature or which contains an amine group ; moreover the 

 osones are easily oxidised in the presence of alkalies [Fischer, Ber. 

 xxii. 87], and in the presence of acid oxidising agents they seem to 

 lose two carbon atoms to yield a dihydroxybutyric acid [Morrell 

 and Crofts, J.G.8. lxxxi. 666]. 



