NA TURE 



445 



THURSDAY, JULY 



I9I3- 



.4 A' EPITOME OF GEOMETRICAL 

 CRYSTALLOGRAPHY. 

 Siatische und kinetische Kristalltheorien. By 

 Dr. J. Beckenkamp. Erster Teil. Pp. viii + 

 200. (Berlin: Gebruder Borntraeger, 1913.) 

 Price 9.60 marks. 



THE style of this book recalls that of parts of 

 the " Eneyclopridie d. math. Wissen- 

 schaften." A summary is given of practically the 

 whole of geometrical crystallography, both experi- 

 mental and theoretical. There is included, for in- 

 stance, an account of crystalline symmetry and 

 structure theory, together with a description of the 

 common types of twinning, habit. Sec. Physical 

 crystallography, including the optical, elastic, and 

 electrical behaviour of crystalline media, lies out- 

 side the scope of the book. 



It will be readily realised that so large a field 

 cannot be adequately covered in 206 pages. The 

 author confines himself almost entirely to the 

 quoting of results. For example, formulas are 

 given to obtain the most probable values of the 

 true angles between four crystal-faces from the 

 observed angles, and also formula? for calculating 

 the angles between these four faces and the re- 

 maining faces ; but no indication is given of the 

 method of arriving at these results. Again, 

 though the thirty-two crystal classes are described 

 in detail, no proof is given of the fact that there 

 are exactly thirty-two classes — and similarly 

 throughout the treatise. 



Dr. Beckenkamp is evidently interested in the 

 history of crystallography ; and he begins each 

 section with a historical summary of work done 

 f>n the subject-matter of that section from the 

 earliest days of the science, with quotations from 

 various authors and valuable references. 



The book is illustrated by 303 excellent dia- 

 grams, well drawn, and easy to follow except for 

 those illustrating the author's theory of molecular 

 groups, which are on rather too small a scale to 

 be clearly visible. 



The style of the work is clear and interesting, 

 and the book is divided into sections of a con- 

 venient length, so that the reader is not tired by 

 over-concentration on a particular theme. 



The book will be a useful addition to the litera- 

 ture of the subject, especially as a work of refer- 

 ence ; but even the beginner will find it attractive, 

 though he will require to supplement it by some 

 work which goes into more detail. Perhaps the 

 least satisfactory part is that dealing with the 

 author's own structure theory. He has scarcely 

 NO. 2 2 79, VOL. qi] 



succeeded in making his point of view clear; and, 

 in fact, the task of explaining a new structure 

 theory of crystals in six pages without the assist- 

 ance of a single mathematical formula would lie 

 beyond the powers of any writer. But doubtless 

 this will be remedied when part ii. appears. 



Harold Hilton. 



.4 HISTORY OF CHEMISTRY. 

 A History of Chemistry from the Earliest Times 

 till the Present Day. By the late Prof. J. C. 

 Brown. Pp. xxx + 543. (London: J. and A. 

 Churchill, 1913.) Price 10s. 6d. net. 



THE late Prof. Campbell Brown, of the Liver- 

 pool University, was in the habit of 

 delivering annually a series of lectures on the 

 history of chemistry to his senior students as part 

 of their degree course, and he had the intention, 

 on his retirement, of preparing these lectures for 

 publication. His sudden and unexpected death 

 while still in the occupation of his chair prevented 

 him from personally realising his wish. Mrs. 

 Campbell Brown, with the assistance of Mr. Henry 

 H. Brown, and Prof. Brown's late chief assistant, 

 Mr. W. H. Roberts, has, however, soiight to 

 give effect to his intention, and the present hand- 

 some volume is the result of their labours. Its 

 compilation has obviously been a labour of love, 

 and forms a fitting memorial to a singularly earnest, 

 conscientious, and high-principled man who played 

 a notable part in the educational history of Liver- 

 pool, and particularly in the creation and develop- 

 ment of its University. Its preparation for press 

 must have been a matter of no little difficulty, and 

 the form in which it is now presented reflects 

 great credit upon Mr. H. H. Brown and his 

 coadjutor. 



The original matter was largely in the form of 

 notes, more or less complete, which the lecturer 

 was accustomed to amplify and comment upon 

 at the moment, and there is little doubt that, had 

 Dr. Brown lived to complete the work, much addi- 

 tional matter would have been included. Possibly, 

 also, some omissions and corrections would 

 have been made in the light of more exact 

 knowledge. The book makes no pretensions 

 to research among original authorities, and it is 

 obvious that the lecturer had been content to 

 take his. facts and interpretations from well-known 

 sources, such as Thomson, Hoefer, Kopp, Meyer, 

 Ladenburg, Berthelot, and others that might be 

 named. In many cases the illustrations, as well 

 as the phraseology, afford the key to the source 

 of the statements. The book is eminently read- 

 able, and may be recommended to the student who 



