June 28, 1906] 



NA TURE 



195 



THE MANUFACTURE OF CYANIDES. 

 The Cyanide Industry Theoretically and Practically 

 Considered. By R. Robinc and M. Lcnglen. 

 Translated by J. Arthur Lederc, Ph.D., with an 

 ;i|)|)i>ndix by C. E. Munroc, Ph.D. Pp. xix4o8; 

 illuslrated. (New York: John Wiley and Sons ; 

 l-iindon : Chapman and Hall, Ltd., iqol).) Price 

 17.V. iicl. 



Tl 1 1\ stiniul.atin;.; effed on industrial research 

 caused by the prospect of immediate material 

 ii:un is strikingly illustrated by the progress of the 

 ( yanide industry. Until cyanide of potassium was ap- 

 plied to the treatment of gold ores, comparatively little 

 interest was taken in its manufacture. The consump- 

 tion amounted to about fifty tons a year only, and the 

 old expensive and wasteful methods of obtaining it 

 from ferrocyanide which had been made by the use of 

 nitrogenous organic substances were detMiied sufficient 

 for the purpose. When the demand was rapidly grow- 

 ing in the 'nineties there was a rush of investigators 

 to discover new and cheaper methods of manufacture. 

 .\ fair amount of success was attained, and some 

 thousands of tons of cyanide are now produced annually 

 in Great Britain and Germany and sold at one-third 

 the former price. The older processes have been 

 .ibandoned and new ones introduced, and, although 

 some doubt still remains as to the future of the 

 industry, the field for useful research has been nar- 

 rowed, and once again offers little attraction to the 

 chemical "pot-hunter." Comparatively little cyanide 

 is produced in France, however, and apparently it 

 was the apathy of their fellow-countrymen on the sub- 

 ject which induced MM. Robine and Lenglen to write 

 the book which has just been translated. 



The authors divide their book into four parts, of 

 which part iii., on the methods of manufacturing 

 cyanide com]X)unds, is alone of any real importance. 



Part i., occupying sixty-five pages, deals with the 

 chemistry of cyanogen and its derivatives. It con- 

 tains no correct statement that does not appear in 

 ordinary te.xt-books of chemistry, and is distinguished 

 by an extraordinary number of misprints or mis- 

 statements, such as " cyanogen does not unite 

 directly with hydrogen," "it [cyanogen] becomes a 

 liquid at 2o°.7 under ordinary pressure," and " If the 

 cyanide contains chlorides, the method [of estimation 

 of cyanide by means of silver nitrate] is not accurate." 

 There are no references to the sources of information, 

 and the whole section seems to have been drawn up 

 in a perfunctory way. 



Of even less value is part ii., which occupies twelve 

 pages, and is on "The Present Condition of the 

 Cyanide Industry." None of the information given 

 in this part appears to be of later date than 1901, 

 and some of the tables of figures end in 1896. The 

 tables refer mainly to France, but there is a list of 

 works producing cyanide compounds which applies 

 to the whole world. 



Part iii. occupies 213 pages, and gives a clear 

 account of a very large number of methods of manu- 

 facture, most of which, as the authors are careful 

 to point out, have never been successful on an in- 

 NO. 1913, VOL. 74] 



duslrial scale. All the chief cyanide compounds are-' 

 dealt with, and separate chapters are devoted to the 

 manufacture of cyanides, ferrocyanides, ferricyanides, 

 and sulphocyanides. Sulphocyanides and, to a less 

 extent, ferrocyanides owe their importance to their 

 use in the preparation of cyanides, but the authors 

 devote most attention to the interesting direct syn- 

 thetic processes of making cyanides from carbon and 

 nitrogen or ammonia. 



The fixation of atmospheric nitrogen is a fascinating 

 problem which is likely to continue to exercise the 

 minds of chemists, and the translator, as an agri- 

 cultural chemist, expresses the daring ho|)e that the 

 publication of this volume will result in the solution 

 of the problem on an industrial scale. It is, of course, 

 well known that cyanides are formed in blast fur- 

 naces, and many attempts have been made to apply 

 this knowledge, beginning with Bunsen's special 

 furnace, which was built in 1845. In most of the 

 later processes, atmospheric nitrogen, freed from 

 oxygen by passing it over heated metals or by dis- 

 tilling liquid air, has been passed over carbides of 

 metals heated in electric or other furnaces, but 

 although some progress has been made, the cyanide 

 industry still continues to depend on more round- 

 about chemical actions. One of these is the synthesis, 

 of sulphocyanide by the action of ammonia on carbon 

 bisulphide in the presence of a base such as lime, fol- 

 lowed by the reduction of the sulphocyanide by means- 

 of carbon, metals, or hydrocarbons. 



Illuminating gas and its residues constitute a source 

 of cyanide which has not been fully exploited. The 

 authors anticipate that in the future a large pro-- 

 portion of the required cyanides will be obtained 

 from gas works, and estimate that in France alone 

 4,000,000 tons of coal used annually in the manu- 

 facture of illuminating gas could be made to yield 

 cyanide compounds worth from eight to twelve 

 million francs, all of which is now lost. In other 

 countries, however, the matter has not been over- 

 looked, and it is certain that the illuminating gas. 

 used in the world could be made to yield far more 

 cyanide than could possibly be disposed of, unless 

 new uses for cyanide should be discovered. The pro- 

 gress of the cyanide industry is checked rather by 

 well-founded fears of overstocking the market than 

 by the neglect by manufacturers of their opportunities 

 or by the need of fresh sources of supply. 



In part iv., which occupies twenty-seven pages, 

 there is an adequate account of the use of cyanogen 

 compounds, and this is followed by an appendix of 

 seventy-one pages. Here a digest is given of the 

 Lnited States patents relating to cyanide processes for 

 the recovery of the precious metals. No doubt the 

 list is fairly complete, but it has nothing to do with 

 the main subject of the book, and does not contain 

 any reference to patents relating to the manufacture 

 of cyanides. However, as it shows the activity of 

 the consumers of cyanide, it may be taken as a tonic 

 by disheartened manufacturers, who, after all, are 

 probably more interested in markets than in chemical' 

 formulas. T. K. Rose. 



