REVIEWS 671 



of the Adh^ves Research Committee. An appendix deals more espedally 

 with the electrometric and indicator nethods of detennimng hydrlon 



concentrations. 



The book is well printed and very few misprints have been noticed. 

 One sentence on p. 141 reqtrires revision, and the choice of acetic acid to 

 illustrate the propCTiies of an amphoteric substance (p. 221) seems very 

 unfortunate. The hterature references given are very full, but not quite 

 complete ; they are amply sufficient, however, for the object the author 

 had in \-iew, namely, to give a oonnected and clear account of the chemistry 

 and technology of gelatin and glue. T. 5. P. 



Research^ on CeDnlose, rv (1910-1921). By Charles F. Cross and Chari.zs 

 DoRnE. T*?- ^ 2> 253, with four plates and 12 diagrams in the 

 text." (London : Longmans, Green & Co., 1922. Price 15s. net.) 

 This volume is the fourth of the well-known series " Cross and Be»-an," 

 the place of the late Mr. Bevan being taken by Mr. Doree. The long in- 

 ter\-al which has elapsed since the appearance of Part III makes this volume 

 the more welcome, especially as there has been increased activity connected 

 with the scientific and technical problems rdated to cdlulose both during 

 and since the war. The book is divided into se%-en chapters dealing, amongst 

 other subjects, with the Physical Properties and Constitution of Cellulose, 

 while the last three are entitled " Oxyoellulose and Hydrocdlulose," " ligno- 

 ceUtiloses and Lignone," " Cellulose Industries and Technology " respec- 

 tively. The general arrangement is substantially the same as that followed 

 in the earlier volumes, each chapter containing abstracts of a selection of 

 the more important researches dealing with the subject concerned, followed 

 by a short critical sunmiary. This method of treatment is particulaiiy 

 valuable where the author's views are at variance with those of the writer 

 of the paper, for Mr. Cross's experience is of course unrivalled and his 

 opinion is always valuable. Throughout the book he presses his views 

 concerning the mental attitude to be adopted towards ceUulose, namely, 

 that it is "a colloidal substance ' organic ' in function and a^uming, 

 correlatively, highly specialised and infinitely varied structural forms . . . 

 retaining, after separation from the plant, characteristics of reactivity 

 impressed by the conditions of vital origin ; a substance to be investi- 

 gated as it is, therefore rather by physical methods including the methods, 

 of the physiologist and histologist." As an outcome of the continued 

 reiteration of this attitude Mr. Cross is inclined to treat rather unsym- 

 pathetically those purely chemical workers wha attenipt in the first in- 

 stance merely to elucidate the composition of the ^C;H:oO,)n comtlex. 

 as distinct from the naturally occurring colloidal aggregate of the fibre. 

 Resrardine the somewhat elusive ta~ms hvdrocellulose and oxvcellu' =f 

 the authors state that " there are no lines of demarcation or direxeiiiii- 

 tion justif\dng these terms as applied to chemical individuals and that 

 they rather connote reactions and the products represent phases of equili- 

 brium . . .," a statement which can hardly be said to make the pwsition 

 much clearer. With regard to the constitution of LignoceEluloses there is 

 no tendencv shown to recede from the \-iew originally put forward by Cross 

 and Be^-an or to accept any of the views of other workers, although the 

 present authors reveal a sympathetic feeling towards the ph3rsical view of 

 the union between the carbohydrate and the Hgnone, a \dew which receives 

 support from the rather remarkable obser\-ations of Robinson which are 

 interpreted bv this author as " a displacement of adsorbed lignone originally 

 in the form of films overlaying the groxmd ceUulose of the tracheides." A 

 |>erusal of this verv interesting and suggestive volume leaves one with a 

 feeling of the immense complexity of the subject and the distance which 

 has yet to be covered before the complete story can be told. 



