330 SCIENCE PROGRESS 



CHEMISTRY 



A Dictionary of Applied Chemistry. Edited by Sir Edward Thorpe, C.B., 

 LL.D., F.R.S., assisted by eminent contributors. Vol. I, revised and 

 enlarged edition, with illustrations. [Pp. x + 752.] (London : 

 Longmans Green & Co., 1921. Price 605. net.) 

 The manifold applications of chemical science in the Great War, and the 

 general realisation of the fundamental importance of a flourishing chemical 

 industry have made the publication of a new edition of Sir Edward Thorpe's 

 well-known Dictionary oj Applied Chemistry a very desirable and very neces- 

 sary undertaking. 



The style and arrangement of the previous edition has been retained and 

 in general one may say that the volume under review is similar to its pre- 

 decessor, with its good points and its failings magnified. 



On the one hand, several articles have been fully revised, or entirely re- 

 written so that many of them form really reliable short monographs on the 

 subjects dealt with. Such an article as Mr. J. J. Manley's exposition on 

 Precision Weighing, for instance, is well worth studying, and should form 

 a standard reference on the subject. 



On the other hand, however, it is much to be regretted that the volume is 

 still without an index, which renders it valueless for many purposes of quick 

 reference, so that one is compelled against one's will to turn to the inevitable 

 Ullmann's Enzyklopcedie ; and again, there is considerable overlapping of 

 articles and lack of cross-references, which seriously diminish the value of the 

 work. 



As an instance we may take the case of Berberine ; on looking this up 

 on page 584, we find a i J-column article giving a short account of the subject ; 

 apparently, therefore, that is all that there is known about it. 



If, however, one happens to look up Barberry (pp. 534-8) one finds there a 

 long and detailed account of the same product (8 columns), bringing the whole 

 subject up to 1918 ; no cross-reference whatever is given to the latter article 

 under the heading of Berberine. 



This is merely a typical example ; again, the concise article on Azo Dyes 

 by the late Dr. J. C. Cain contains the names of many hundred colours, 

 but no attempt whatever seems to have been made to index them in any 

 place, so that for most purposes the article is almost useless, although, with- 

 out any very apparent reason, one or two names occur here and there in the 

 book, such as " Azo Coccine, see Azo Colouring Matters," but no reference is 

 made to most of the other colours. 



These weaknesses, which detract very seriously from the value of the 

 book as a work of reference, are due chiefly to what one may perhaps term 

 inadequate stafE work, and it is to be hoped that in the later volumes, which 

 are promised soon, these defects will be remedied ; best of all, the last volume 

 might well contain a comprehensive index to the whole Dictionary. 



F. A. Mason. 



Applied Colloid Chemistry. By Wilder D. Bancroft, Professor of Physical 



Chemistry at Cornell University. [Pp. viii -j- 345, with numerous 



diagrams.] (New York : McGraw-Hill Book Company, 192 1. Price 



i8s. net.) 



It is rare to find a treatise on colloidal chemistry written in such an interesting 



manner as this text-book. The empirical nature of the subject, with its 



accumulation of undigested facts, places considerable difficulties in the way of 



comprehensive treatment. The author, in his subdivision of the subject, 



has emphasised the importance of adsorption in colloidal chemistry. In this 



respect he has adopted the classification of Freundlich's Kapillarchemie, 



but the general methods of presentation are very different in the two cases. 



Indeed, the two works are to some extent complementary. It is intended 



