xii Preface to the New Edition 



mixtures containing cuticular cellular products, special attention 

 is necessary in choice of methods of attack. On this section 

 the reader must be referred to a very valuable general study, 

 ' Bestimmung der Zellulose in Holzarten und Gespinstfasern ' : 

 J. Konig and Fr. Hiihn (Berlin, 1912). Although we and 

 others have had occasion to differ from these authors in regard 

 to both methods and results, the general value of the experi- 

 mental matter is not prejudiced thereby, and the brochure 

 should be carefully studied. 



New Derivatives. We may mention a new class of 

 acetic esters of considerable industrial importance, which are 

 prepared according to the Dreyfus patents. In these acetates 

 the degree of acetylation is sensibly below that of the hitherto 

 better known tri-acetates, and they are distinguished by solu- 

 bility in acetone. We have also to note the production of 

 derivatives containing the methoxyl and ethoxyl groups that 

 is, of true cellulose etheis. 1 So far the investigation of these 

 bodies has not thrown much light on the major problems, but 

 they are useful additions to the series of derivatives of cellulose, 

 and are of potential interest as an auxiliary to research. 



Destructive Distillation. An important contribution 

 is that of H. Rollings and J. W. Cobb : ' Thermal Study of 

 the Carbonisation Process' (J. Chem. Soc. 107, 1106). These 

 authors incidentally confirm the statements in the original 

 volume as to the exothermic character of the decomposition of 

 celluloses and ligno-celluloses when heated, and they have 

 added methods of investigation of considerable refinement and 

 general application to organic products of the cellulose-lignite- 

 coal series. An interesting study of the products of destructive 

 distillation is that of E. Erdmann and C. Schaefer [Berl. 



1 W. S. Denham and H. Woodhouse : J. Chem. Soc. 105, p. 2357 

 (1914). 



