APPENDIX II 



IN the period 1895-1900 succeeding the publication of the first 

 edition of this work, there have appeared a number of contribu- 

 tions to the general chemistry of ' Cellulose,' the more important 

 of which have been recorded and discussed in a volume of 

 'Researches on Cellulose' by the present authors, published in 

 1901. 



It will be of interest to our readers to follow the main lines of 

 growth of the subject ; and we therefore give a brief outline, and in 

 very general terms, of these later developments. 



Cellulose. Constitution. An observation of fundamental im- 

 portance is the direct conversion of cellulose into a crystalline 

 furfural derivative under the action of the halogen hydracids. 

 Empirically the reaction in the case of hydrobromic acid may be 

 expressed by the equation : 



C 6 H 10 5 + HBr - 3 H 2 = C 6 H 5 O 2 Br 



the product being a brom-methyl furfural. The condensation 

 takes place readily at 100 C. in presence of anhydrous ether. A 

 particular point of interest arises in regard to the generalisation ol 

 the reaction as one specially characteristic of the ketoses, /.<?. the 

 keto-hexoses. The conversion of the typical levulose is represented 

 as follows : 



1 H H I HH 



OH.C.C. C C C CH 2 OH - OC.C : C.C : C.CH a Br. 

 !H,0:;HOH!jOHHj H 



(H. J. H. Fenton. Chem. Soc. J., 1901, 361.) 



The yields of the w-brom -methyl furfural from various forms of 

 cellulose were found to be high (33 p.ct), higher indeed than from 



z 



