NA TURE 



67 



THURSDAY. NOVEMBER 17, 1910. 



THE CELLULOSE AGE. 



l^ie Chemie der Cellulose urtter besonderer Beriick- 

 sichtigung der Textil- iind Zellstoffitidustrien. By 

 Prof. Carl G. Schwalbe. Erste Halfte. Pp. 

 272. (Berlin : Gebriider Borntraeger, 1910.J Price 

 9 mk. 60 pfg. 



THIS work is created by an opportunity, and in 

 producing it the author has obeyed what in 

 another walk of life would be a "call" — Germany not 

 having produced a text-book or systematic work on 

 this subject, the hiatus is a sufficient raison d'etre 

 for this publication. The author's qualifications as 

 a worker in the field of cellulose promise a worthy 

 fulfilment of his task, and we may say at once, the 

 volume before us — the moiety of the work to be com- 

 pleted in and by a second volume, to appear at the 

 end of this year — is a weighty contribution to the 

 literature of this section of organic chemistry. 

 The general title presages a systematic treatment 

 the subject-matter ; but the plan and method laid 

 \vn are not criticallv selective, and the result is 

 lather a classified account of original investigations, 

 under sectional titles, such as '" Cellulose and 

 i Alkalis," "Cellulose and Acids," "Cellulose and 

 Salts," and "Colouring Matters" and "Oxidants," 

 ' &c. The second part of the volume under the main 

 I title, " Derivatives of Cellulose," deals successively 

 i with ■' hydratcelluloses," "hydrocelluloses," "oxy- 

 kelluloses," " hydracelluloses," "acid celluloses," &c. 

 I The result is in effect a compilation, an edited 

 biblioj^^raphy. In recording this general impression 

 iwe do not wish to detract from the value of the book; 

 we merelv note for the benefit of our fellow-students 

 jthat there is a certain nonconformity of its matier 

 with the title, and the promise of a pioneer work, 

 which it contains, is still unfulfilled. The sub-title, 

 Nith special reference to the textile and wood pulp 

 v^dlstoff) industries," also fails to impress itself upon 

 |the plan or method of treatment, and therefore a 

 |dominating technical aim or Leitmotiv is no more in 

 evidence than the critical scientific. The second 

 kolume yet to appear may modify these impressions ; 

 put we do not anticipate that the work will take 

 {ank otherwise than as an exhaustive bibliographical 

 ■ecord. If we infer that this may be the author's 

 ntention, it is because we have no special or self- 

 vealing preface (Vorwort), only a general introduc- 

 n (Einleitiiug), and the reader is left to form his 

 'inclusions. 

 Following the short introduction in which tech- 

 ical. rather than scientific generalities are prominent, 

 e are confronted at once with the full complexity 

 cellulose in the title of section i, "Die Baumwolle- 

 lulose Luft und Licht." To open with the 

 'blems connoted by this title is indeed to build 

 •:n the top, upon foundations laid in the air. A 

 rely a priori analysis challenges all we know plus 

 well-defined estimate of what we do not know of 

 ■llulose as a chemical individual, in being. The 

 NO. 2142, VOL. 85] 



next section, " Baumwollecellulose und Elektrizitat," 

 continues to occupy the reader with problems of much 

 complexitv and obviously of the most general import. 

 The phenomena and reactions involved are those of 

 the cellulose aggregate, of which nothing can be 

 affirmed. Section 4, " Die Baumwollecellulose bei 

 Warmezufuhr," continues the study of the aggregate 

 in relation to energy. The series of decompositions 

 presented by destructive distillation are infinitely 

 varied, and pyrogenetic products of resolution are 

 generally the least simply related to the parent sub- 

 stances or molecules ; the author does not attempt 

 this genealogical investigation. 



We notice in passing that no mention is made 

 either of the specific heat or heat capacity of cellu- 

 lose, or of the physical phenomena, such as changes 

 of volume and dimensions, within the range of tem- 

 perature — i.e. up to 150° — which conditions the per- 

 sistence of cellulose as a chemical individual. Since 

 cellulose and many derivatives are now produced in 

 the form of solids of regular and controlled dimen- 

 sions, this important direction of physical investiga- 

 tion is opened up. 



The following and main sections are devoted to the 

 changes determined in the cellulose complex by the 

 action of acids, alkalis, and salts and oxidants, and 

 its relations to colouring matters and "mordants," 

 generallv to such compounds which enter into what 

 it is now fashionable to call "adsorption " combination. 

 It is particularly in the treatment of the complex 

 phenomena attending hydration, hydrolysis, and con- 

 densation, that the author should have adopted a 

 critical method. A " genial " drawing is worth a 

 volume of photography, and if the author had trusted 

 himself as impressionist rather than camera artist he 

 would have used his great opportunity to more 

 adequate purpose. No chemist regards "hydrocellu- 

 lose," "h%dracellulose," " hydratcellulose," "oxycellu- 

 lose," as terms defining chemical individuals ; they 

 connote a more or less definite equilibrium of action 

 and reaction within the cellulose agg^regate, which is 

 susceptible of infinitely varied " schemes " of degrada- 

 tion ; these are better classified in relation to the 

 determining conditions than in terms of presumed 

 end-products. The alternative method, with the con- 

 scientious discharge of the duties of an " all-truistic " 

 bibliographer, leaves the reader without mental pic- 

 tures which are the pleasurable reward of the dili- 

 gent student. Students of the natural sciences bewail 

 a tendency to over-population of their book-world as 

 of other "worlds." The literature of cellulose is 

 alreadv of formidable dimensions, and yet its funda- 

 i mental chemistry can be set forth on the proverbial 

 "half-sheet of notepaper." 



The present phase of diffuse expansion in the re- 

 gion of "cellulose" and other typical colloids calls 

 for a more critical attitude of workers and investi- 

 gators, both in the researches undertaken and the 

 extent of their records. 



We may note in conclusion that the volume, in 

 paper covers, weighs 733 grams. It involves there- 

 fore a considerable weight of cellulose; and, more- 

 over, the printing and finish of the volume are un- 

 usually excellent. 



D 



