July 28, 192 1] 



NATURE 



677 



who will appreciate it are medical men in practice 

 as Medical Officers of Health, many of whom 

 find gfuidance in this connection necessary occa- 

 sionally. 



"Hewlett and Nankivell," as the book will in- 

 evitably be called, is certain of a great welcome, 

 and equally certain to be classed as good. The 

 feeling cannot, however, be escaped that it would 

 have been better if the authors had avoided the 

 faults in style to which reference has been made. 

 In the second edition, which, no doubt, will soon 

 be required, an opportunity for dropping some of 

 the more lurid of the descriptive matter will occur, 

 and it is to be hoped that the space thus released 

 may be utilised for the presentation of some illus- 

 trations in addition to, or even in place of, a 

 number of the charts and diagrams which alone 

 adorn the present edition. 



Non-Ferrous Metallurgy. 



Handbook of Metallurgy. By Prof. C. SchnabeL 

 Translated by Prof. H. Louis. Third edition, 

 revised by the translator. Vol. i., Copper — 

 Lead — Silver — Gold. Pp. xxi-}- 1171. (London: 

 Macmillan and Co., Ltd., 192 1.) 405. net. 



THIS well-known work on the metallurgy of 

 the non-ferrous metals was first made 

 available to the English metallurgist in 1898 by 

 Prof. H. Louis. At that time there was not, in 

 the English language, a complete treatise on this 

 branch of the subject, and it was at once recog- 

 nised that the book was an addition to our litera- 

 ture. The fact that Prof. Louis had rendered 

 metallurgists a valuable service receives confirma- 

 tion in the demand for a third edition. In pre- 

 parinp- this new edition, Prof. Louis wisely decided 

 to bring the work up to date himself, and not to 

 wait for the publication of the third German 

 edition, for, as he states in the preface, "all the 

 important modern improvements in metallurgical 

 practices are to be found in English-speaking 

 countries." 



A work of this kind, which covers such a wide 

 field, takes considerable time to revise, and the 

 war, having intervened during its preparation, has 

 prevented some of the more recent developments 

 from being recorded ; but, in spite of this, the 

 book will be found to be most useful and to have 

 distinct value. 



The volume which is now published deals with 

 the metallurgy of copper, lead, silver, and gold. 

 The original form of the work is still maintained, 

 but the previous edition has been increased by 

 about forty-five pages. The actual addition of 

 new matter is greater than is represented by this 

 increase, for obsolete processes have been deleted. 

 NO. 2700, VOL. 107] 



Considering the progress made in recent years, it 

 is evident that Prof. Louis has had a difficult task 

 in including the descriptions of modern methods 

 without seriously increasing the size of the 

 volume. For this reason the cutting down of 

 the older processes might perhaps have been 

 somewhat more drastic. Some of the processes 

 described under silver, and also the "chlorination 

 process " for the extraction of gold, have not a 

 wide application at the present time, and are 

 scarcely worthy of the space they have been 

 allowed. 



Besides the general revision, the section on cal- 

 cination furnaces in the part on copper has been 

 extended, the chief furnaces being described ; also 

 a concise description of the blast-roasting of 

 copper ores is given, and the section on the Bes- 

 semer process of copper extraction has been en- 

 larged. Among the additions made under lead 

 are : The Savelsberg process, blast-roasting with- 

 out lime, pot-roasting, and down-draught sintering 

 processes. The part devoted to gold has received 

 much attention, and has been improved by a clear 

 and, in the space available, complete account of 

 the cyanidation process- -fine-grinding, various 

 methods of classification, and the " all-slime pro- 

 cess " being included. 



There are two points open to criticism. In 

 regard to the original matter, no indication is 

 given that any of it has become of less practical 

 value ; consequently, students may receive the im- 

 pression that some of the older processes are as 

 important as, or even more important than, some 

 of the chief modern methods. Moreover, the 

 retention of a statement such as " the more recent 

 form of " made in connection with the description 

 of a plant which was given in the first edition 

 twenty-three years ago is liable to be misleading. 



The volume, as a whole, is comprehensive and 

 accurate, and can be recommended with con- 

 fidence. Prof. Louis is to be congratulated on 

 having prepared this new edition and brought the 

 book up to date. It is a pity that most readers 

 will not be able to determine which is really the 

 translator's work and so to judge of its excellence. 



E. C. 



The Confidences of Men of Science. 



The Purple Sapphire, and other Posthumous 

 Papers. Selected from the Unofficial Records 

 of the University of Cosmopoli by Christopher 

 Blayre. Pp. x-f-2io. (London: Philip Allan 

 and Co., 1921.) >^s. 6d. net. 



THE author — or, to be more accurate, the 

 editor — of this fascinating but blazingly 

 indiscreet volume refers to Nature as " that 



