Mr Jackson, Researches in the Sugar Group. 215 



Researches in the Sugar Group. By Mr H. Jackson. 



[Bead 27 November, 1899.] 



In the present paper a summary is given of the joint researches 

 of Mr H. J. H. Fenton and the author, which may be conveniently 

 divided into two parts. 



(a) Oxidation of the more common polyhydric alcohols. 



The remarkable part which iron plays as a carrier of oxygen 

 was first pointed out by Mr Fenton in the case of tartaric acid, 

 and has since been extended by him to other hydroxy-compounds. 



An aqueous solution of the following polyhydric alcohols, glycol, 

 glycerine, erythrite, dulcite, mannite and sorbite, was taken in turn, 

 and after adding a small quantity of ferrous salt to each, hydrogen 

 peroxide was added : in all cases a large evolution of heat took 

 place. The oxidation products in the case of glycol, glycerine and 

 erythrite quickly reduce Fehling's solution in the cold and restore 

 the colour to an alcoholic solution of magenta, which has been de- 

 colourised by sulphur dioxide : on treatment with phenyl hydrazine 

 acetate, osazones were obtained which, on analysis, were found to 

 correspond respectively to glycolic aldehyde or diose, glyceric- 

 aldehyde or triose, and erythrose or tetrose. 



The oxidation compounds of dulcite, mannite and sorbite do 

 not reduce Fehling's solution in cold, but quickly on warming: 

 they do not give the " magenta " test : facts which serve to dis- 

 tinguish the hexoses from the simpler members of the sugar 

 group. On treatment with phenyl hydrazine acetate there was 

 obtained from dulcite the osazone of inactive galactose, from 

 mannite the hydrazone of mannose, and from sorbite an osazone 

 identical with glucosazone. 



If an aqueous solution of glycol, glycerine or erythrite, to 

 which a very small quantity of ferrous salt has been added, be 

 exposed for a little time to the action of sunlight in the presence 

 of atmospheric oxygen, it can be shown on examination that a 

 certain amount of the sugar has been formed. 



These experiments may perhaps give a little support to the 

 theory that iron, which occurs in haemoglobin and is associated so 

 intimately with chlorophyll, may act as a carrier of atmospheric 

 oxygen. 



