NA TURE 



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THURSDAY, NOVEMBER i6, 191 1. 



CELLULOSE DERIVATIVES IN THE SERVICE 

 OF MAN. 



Mtrocellulose hidustry : a Compendium of the History, 



Chemistry, Ma>infactiire, Commercial Application, 



and Analysis of Nitrates, Acetates, and Xanthates 



cf Celhdose as Applied to the Peaceful Arts ; with a 



Chapter on Gun-Cotton, Smokeless Powder, and 



Explosive Cellulose Nit/ates. Bv Dr. Edward C. 



W'orden. Vol i., pp. xxxiv + 565. Vol. ii., pp. 



xxviii + 567-1239. (London: Constable and Co., 



f.td., 191 1.) Price, two vols., 425. net. 



TTTHEX Schonbein first announced his discovery 



» '^ of i^un-cotton little could he have foreseen that 



he was laying" the foundation of so many important 



industries as those, sixty-five years later, associated 



v\ith cellulose derivatives, for although the acetates 



Mu! xanthates of this parent substance are daily grow- 



: in importance, their introduction has solely been 



Kit to the wide and successful application of the 



litrocelluloses. One may safelv say that the deriva- 



!i\es of no other sing^le chemical substance (if cellulose 



in its varied forms may be so termed) have proved 



if such general use to mankind, assisting" in the pro- 



luction at a cheap rate of numbers of articles hitherto 



nade from expensive natural products, developing 



m|)ortant branches of photography, rendering valuable 



-I rvice to the man of science and medical man, and 



•inallv furnishing the base of all the modern smokeless 



lowders. The author has succeeded in these two com- 



irthensive volumes in admirably treating of all the 



iiscoveries and applications of these highly important 



If rivatives. The magnitude of such a work and the 



hnroughness with which it has been carried out may 



H realised from the fact that more than 8000 literature 



I lirences and 15000 patent references have been veri- 



Ird. 



Ihe preparation of the nitrocelluloses and their 



t.il)ilising is of the first importance, and is very clearly 



ifalt with. An important point is the effect of prior 



!■' atment of the cotton, before nitration, on the char- 



r of the product and its stability. In general 



Ion treated with bleaching" powder solutions or 



ncrcerised by alkali g"ives a lower nitrogen content, a 



■I rater ether-alcohol solubility, and renders subsequent 



tahilisalion more difficult. 



'I he successful application of nitrocelluloses in the 



rts is almost wholly dependent on the use of proper 



"Ivcnts and obtaining solutions of the desired vis- 



"^ity. The important part which amyl alcohol {iso), 



iitroduced by .Stevens in 1882, has played in the 



nilicial If'alher, lacquer, and other industries is 



laralli led 1)\- the iinportanl property of camphor in 



aing solid or suitable plastic bodies for other 



rhes f)f thr iiidiislry. The author estimates that 



lai' 450, ()()() gallons of amyl acetate are annually 



"ipl(>\<d in tlif Ignited States, so that he rightly 



■lis (-onsidiTalilc spare to its pnparation and the 



aistrv of caniijhor also receives vtry full treatment. 



^pa(( does not permit of more than a brief refer- 



-NO. 2194, VOL. 88] 



ence to the numerous applications of nitrocellulose or 

 the other derivatives ; it seems that in one way or 

 another they must have some interest for everyone, 

 but especially for those engaged in any branch of 

 science. The preparation of museum specimens, and 

 particularly of sections for the microscope ; for pre- 

 servation of important writings by saturation of the 

 paper (where Indian ink has been employed, of which 

 shellac is a constituent and soluble in the nitro- 

 cellulose solvent — the paper must first be immersed 

 in a 2 per cent, solution of gelatin and allowed to 

 dry) ; for the production of special tubes for deep-sea 

 soundings, the tubes being coated inside with silver 

 chromate, are amongst the minor but still important 

 applications of nitrocellulose solutions. 



In the large industries built up on cellulose deriva- 

 tives during the last twenty years mention may be 

 made of its application in the manufacture of incan- 

 descent mantles, both for coating the mantle to enable 

 it to withstand the shocks of transport and handling, 

 and the production of mantles themselves by the 

 ejection of filaments containing the thoria and ceria, 

 to be afterwards woven into mantles ; the production 

 of pyroxylin containing imitation leathers, of which 

 a conservative estimate of the daily output of the 

 United States is 45,000 yards, and for photographic 

 purposes, where the applications of soluble nitrocellu- 

 loses are so numerous that considerable space is 

 devoted to the subject. The production of continuous 

 films has undoubtedly contributed more than anv other 

 discovery to the popularity of photography, and ren- 

 dered the kinematograph a possibility. The extreme 

 desirability of using non-inflammable films is empha- 

 sised from time to time by the ignition of ordinary 

 films, so that the description of the preparation of 

 cellulose acetate films will prove of value and a useful 

 guide to future inventors. 



The production of artificial silk is a triumph of the 

 application of chemical substances to rival one of the 

 most beautiful products of nature. Whilst in the early 

 days it was thought to be a rival to the natural pro- 

 duct, its lack of flexibility and strength have precluded 

 this actually being the case ; but the beauty of the 

 filaments has given rise to so many new and decorative 

 materials that, although not a rival, the demand for 

 the artificial product was, for a period, so great that 

 its price actually exceeded that of the natural silk. 

 A brief reference can only be made to the early process 

 of Chardonnet (1884), in which, as in most processes, 

 an ether-alcohol solution of nitrocellulose is employed. 

 The fluid was at first squirted through an orifice 

 o'5 mm. in diameter, the spinnarets falling into cold 

 water which coagulated, their exterior forming a tube 

 with a liquid interior, this coarse thread being then 

 rapidly spun out into a thin filament. Later the 

 orifice was reduced to o'o8 mm. Nitroeellulos,' silks 

 are usually denitrated by means of an alkaline sul- 

 phide, so that finally they are essentially cellulose. 

 It is of interest to compare the diameter of the arti- 

 ficial fibre with the natural. Chardonnet silk is given 

 as 45 to 60 niicromillimetres, while ihe natural silk 

 is onlv () to 15, these figures being for the wet 

 (swollen) fibres. 



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