Messrs Morrell and Crofts, Modes of Formation of Osones. 119 



progress, and we hope at an early date to be able to make a com- 

 munication on the results, which so far promise to agree with 

 what was predicted. In the formation of the osones from hexoses 

 or pentoses by the action of hydrogen peroxide in the presence of 

 ferrous sulphate, it is advisable to allow part of the ferric iron 

 formed during the oxidation to return to the ferrous state, before more 

 hydrogen peroxide is added. When sufficient hydrogen peroxide 

 has been added, one gram molecule of hydrogen peroxide for one 

 gram molecule of the carbohydrate, the solution is treated with lead 

 acetate and basic lead acetate, filtered, and the filtrate treated with 

 excess of baryta water, whereby the precipitated lead hydroxide 

 withdraws the osone from the solution as a loose lead hydroxide 

 compound. After washing with water, the lead hydroxide com- 

 pound is decomposed exactly by 30 °/ sulphuric acid, and the 

 nitrate concentrated in a vacuum at 50° 0. to a syrup. A certain 

 amount of the osone in the lead hydroxide compound undergoes 

 oxidation during the washing with water, yielding an acid, which 

 gives an insoluble lead salt with normal lead acetate. The syrup 

 containing the osone is not free from the parent sugar. In the 

 case of fermentable sugars, fermentation with yeast will remove 

 the carbohydrate, leaving the nonfermentable osone. The aqueous 

 solution of the glucosone, obtained by this method of oxidation 

 from glucose, reacts readily at the ordinary temperature with 

 phenylhydrazine acetate and also with methyl phenyl hydrazine 

 acetate [Morrell and Crofts, J.C.S. LXXV. 786]. The methyl 

 phenylosazone is identical with that obtained by Neuberg from 

 d fructose [Z. Ver. Rubenzucker Ind. 1902, 237]. Paranitrophenyl- 

 hydrazine dissolved in glacial acetic acid reacts immediately 

 with glucosone at the ordinary temperature. The dark red 

 osazone possesses the same melting-point as that obtained from 

 the action of nitrophenylhydrazine on d glucose at 100° C. All 

 these osazones were analysed and their melting-points compared 

 with those obtained directly from d glucose or d fructose. 



Glucosone obtained from d glucose or d fructose is feebly opti- 

 cally active. It is very soluble in water, in hot alcohol, and is 

 insoluble in acetone or ether. On treatment of a methyl alcohol 

 solution of glucosone with acetone the glucosone is precipitated as 

 an amorphous powder, which on analysis gives numbers corre- 

 sponding to the formulae C 6 H 10 O 6 or C 6 H 12 6 . The amorphous 

 solid possesses the characteristic properties of osones. [Morrell 

 and Crofts, J.C.S. lxxxi. 666.] 



Glucose is not the only carbohydrate which, on oxidation with 

 hydrogen peroxide in the presence of ferrous sulphate, yields an 

 osone. If d fructose is oxidised with these oxidising agents, gluco- 

 sone is formed, which possesses all the properties of the same 

 substance obtained from glucose. Mannose also yields the same 



