110 



Journal of the Mitchell Society. 



{Nov, 



dilute hydrochloric acid at 100°. The percentage yields of 

 reducing products equal to dextrose were as follows: cotton, 

 3.29; starch, 98.6. Fenton and Gostling have brought out 

 another striking behavior. Cotton cellulose is acted upon by 

 dry hydrobromic acid in ethereal solution producing w-Brom- 

 methylfurfural, a 33 per cent, yield being obtained. Under 

 the same treatment potato starch yielded only 3.7 per cent. 

 The belief is growing that cellulose does not belong to the 

 straight chain compounds with the sugar and starches, but is 

 instead a ring compound. Three formulae have been proposed 

 for the unit group, C 6 H 10 O s , as follows: 



CO 



/ * 

 CHOH 



Cross and Bevan's, . | 



CHOH 



I 



CHOH CHOH 



Vignon's, 



Green's, 



^ / 

 CH 2 



O CH— CHOH 



I I 

 O CHOH; 



CH a — CH— CHOH 

 CHOH— CH— CHOH 



CHOH- 



O 



I 

 H-CH 



Any general theory of dyeing must take into account the 

 constitution of cellulose. The three theories which have been 

 held are (a) the mechanical, (b) the solid solution, and (c) 

 the chemical. In view of the diverse chemical character of 

 the three most important textile materials, silk, wool and 

 cotton, it seems improbable that one theory will ever occupy 

 the field to the exclusion of the other two. There are 

 no reasons a priori for not combining the three by select- 



