I 



292 



NA TURE 



[January 26, 1905 



of his task he has been eminently successful. In his 

 appeal to a wider public, it is to be hoped that the 

 difficulties of " treating the wider and deeper general- 

 isations of natural science as fit subject-matter for 

 current thought and literature " will not deprive him 

 of a further measure of well merited success. 



T. M. L. 



THE CYANIDE PROCESS. 

 Cyaniding Gold and Silver Ores. A Practical Treatise 

 on the Cyanide Process ; embracing Technical and 

 Commercial Investigations, the Chemistry in 

 Theory and in Practice, Methods of Working and 

 the Costs, Design and Construction of the Plant 

 and the Costs. By H. Forbes Julian and Edgar 

 Smart. Pp. xx + 405; illustrated. (London: C. 

 Griffin and Co., Ltd., 1904.) Price 21s. net. 



THE cyanide process is still in its teens, but it is a 

 lusty stripling. Much of the enormous increase 

 in the production of gold during the last few years is 

 due to it, either directly or indirectly. There are few 

 gold mines of anv importance in the world at which 

 the process is not installed, and it has been stated on 

 high authority that the majority of these mines could 

 not earn profits and pay dividends without its aid. 

 Owing to the shortness of the time since the industry 

 of cyaniding gold and silver ores began to spring up, 

 there is a lack of data on the subject readily available 

 to men at work far from centres of civilisation. There 

 are many books on the cyanide process, but new ones 

 are still welcome, particularly a work like that of 

 Messrs. Julian and Smart, in which some degree of 

 •completeness is attained. 



TTie authors were well equipped for their task, both 

 having been engaged in the industry for a number of 

 vears. They have not, however, merely written down 

 the results of their own practical experience, a course 

 which usually leads to dogmatic assertion on doubtful 

 points, but, on the contrary, have studied the 

 voluminous literature of the subject with evident care, 

 and displayed some judgment in their extractions. If 

 thev had added a bibliography, one shudders to think 

 ■of the portentous length it would have attained. 



Not content with this, they have made a number of 

 laboratory experiments on the dissolution and pre- 

 cipitation of gold, and advance views based on these 

 which are in part novel and somewhat unsatisfactory. 

 Exception may fairly be taken to this portion of the 

 book, for whether these views are right or wrong, they 

 are out of place in a text-book until they have been 

 discussed adequately. To the practical worker, for 

 whom this book is intended, theories are useful only 

 if they explain and elucidate phenomena with which 

 he is confronted in the mill, or enable him to decide 

 on a course of action in unusual cases. Much of the 

 authors' theorising does not appear to answer this 

 test verj' well. 



The book begins with an interesting, if not an 



impartial, chapter on the early history of the cyanide 



process. The authors next proceed to describe the 



laboratory experiments which are necessary to deter- 



NO. 1839, VOL. 71] 



mine the method of applying the process to any par- 

 ticular ore. In the useful discussion on sampling, the 

 omission of any reference to recent work is noticeable, 

 and the account of automatic machines is hardly 

 adequate. 



The most serious omission in this section, however, 

 is in regard to laborator\' work in connection with a 

 mill in operation. The examination of mill solutions 

 for gold and other metals, for available cyanide, for 

 oxygen, or for dissolving power is not touched on. 

 The only reference to the matter is in the sentences : — 



" It must however be understood that there is no 

 relation between the (total cyanide) found present and 

 the dissolving action of the solution on gold and silver. 

 For this reason two different solutions containing by 

 the test the same quantity of cyanide may have very 

 different dissolving effects." 



This would be cold comfort to anyone who wished 

 to learn what he could of the methods adopted to deter- 

 mine the condition of a mill solution. The gap should 

 be filled in a future edition. 



The later chapters, dealing with the methods and 

 machinery used in practice, form by far the most 

 interesting and useful part of the book. The authors 

 seem to be quite at home in describing the design 

 and construction of leaching vats, precipitation boxes, 

 pumps, launders, sizing plant, and all the accessories 

 of a modern cyanide mill. The methods of treating 

 different classes of material are also handled with skill 

 and judgment, and are fairly up to date. It is not the 

 fault of the authors that progress in the industry con- 

 tinues to be rapid, and that any description is behind 

 the times almost as soon as it is printed. The book 

 ends with a couple of excellent chapters on the cost 

 of constructing plants and of treating ores, and the 

 index has been carefully prepared. 



The volume is handsomely got up, and enough has 

 probably been said to show that the merits of the work 

 so far outweigh its faults that those interested in the 

 cyaniding industry cannot do without it. 



T. K. R. 



OUR BOOK SHELF. 

 Fireside Astronomy. By D. \V. Horner. Pp. 105. 



(London: Witherby and Co., 1904.) Price is. Cid. 



net. 

 " The articles which go to make up this little book 

 originallv appeared in the ' English Mechanic and 

 World of Science,' and caused some discussion 

 therein." This we read in the preface of the book 

 before us, and we are further told there that this 

 " simple worded treatise " is intended for the " man 

 in the street." 



.\ perusal of these pages will, however, tend to 

 bewilder the mind of this very practical personage con- 

 siderablv, for the text is not a specimen of clearness, 

 and the illustrations are very far from being self- 

 explanatorv ; in fact, the latter are as bad as it seems 

 possible for illustrations to be. 



In justification of these statements it may be re- 

 marked that the zodiac is mentioned on p. 3 and 

 defined on p. 14. On p. 4 we have a very ambiguous 

 statement about the various altitudes of the sun at 

 different seasons of the year, no reference being made 



