22 Dr Fenton and Mr Berry, Studies on Cellulose Acetate 



C12H15O5 (0C0CH3)5 + CgHsONa + 4C2H5OH 



= CiaHigOgONa + 5CH3COOC2H5 



which may be taken to represent the main reaction. 



In support of this, the yellow sodium compound from a similar 

 experiment, after thorough washing with alcohol, was digested 

 for several hours in a reflux apparatus with excess of methyl iodide, 

 and the methoxy group in the resulting product determined by 

 Zeisel's method. The result obtained was 9-2 per cent, of methoxyl , 

 in agreement with that calculated for the formula C12H19O9OCH3. 



The adsorption of basic dyestuffs by cellulose acetate. 



Certain dyestuffs, such as gentian violet are adsorbed in con- 

 siderable quantities from aqueous solution by cellulose acetate, 

 the solid being coloured blue. Cellulose, it is true, also adsorbs 

 the dye, but to a much smaller extent, and the solid becomes 

 violet. This property may be utilized to identify unaltered cellulose 

 in commercial preparations of cellulose acetate. Methyl orange 

 gave negative results, but methyl red was adsorbed in considerable 

 quantity, the solid becoming red. Free dimethylaminoazo benzene 

 gave negative results, but the hydrochloride of this base was 

 strongly adsorbed, the solid cellulose acetate assuming a pinkish 

 yellow colour and the colour of the aqueous solution being almost 

 completely discharged. 



The authors desire to express their grateful thanks to Mr J. W. 

 H. Oldham, M.A., of Trinity College, for much valuable assistance 

 in connexion with this investigation. Mr Oldham has also carried 

 out a large number of experiments on the influence of the mode of 

 preparation upon the resulting properties of cellulose acetate, and 

 it is hoped that his results when completed may form the subject 

 of a future communication. 



