NATURE 



I HURSDAY, 0( rOBl R to, tgi8. 



I HE METALLl RG OF ZINC. 

 The Zinc Industry. By E. \. Smith. ("Mono 

 graphs on Industrial Chemistry.") Pp. vm I 22 3- 

 (London: Longmans, Grei .mil ( "n., 1918.) 

 Price 10s. "1/. net. 



1) VI 1 1 ER more than t yeai s ago Qn 



^- American metallurgist, in opening a dis- 

 cussion on the metallurg) ncj said wittily: 

 "It is a time-honoured custom throw bricks at 

 the zinc man. The accusation is that he has 

 borrowed a lime kiln and a gas retort and pan 

 pf a sui] ai id plant, hiti hed them togi 

 mil spent the lasl fift) years in regarding with 

 holj veneration the reactions ivhich take place in 



i pper man who thinks of zinc 



as something ivith which coppi is adulterated to 

 make brass, and the iron man who regards it as 

 ' of paint for corrugated sheets, and the 

 lead man whose '.pinion as to /inc is not lit for 

 publication, have long fell thai when two or three 

 of tlii minor details of their respective metal- 

 lurgies Hi-re put in order, the) would take a lew 

 days and fix up zinc on a modern basis." 



It 1^ true that there have ieen no such spec- 

 tacular changes in the metallurgy of this metal 

 as were ■ rought in that of steel and copper by the 

 introduction of converters. Nevertheless, it is 

 quite untrue to state, as is sometimes done, that 

 there ha m its metalling 



the first lielgian furnaces wen l>uilt in the early 

 century. The main reason u by 

 11 revolutionary 1 hange is that the 

 chemi tii differs radically from that of the 



other metals, and that these differences control the 

 type ' 'I apparatus that can b< u ed. 



tn the firs! place, the temperature at which this 

 metal is reduced by carbon from its oxide is con- 

 siderably above its boiling-point under atmo- 

 spherii pressure. It is, therefore, always pro- 

 duced as a vapour. In the second place, in order 

 btain a merchantable producl this vapour must 

 be condensed at a temperature considerably above 

 the melting-point of the metal. In practice, the 

 temperature-range is from about 900 to 415° C. 

 Above 900 C. the vapour is not condensed at all; 

 below (is, C. it freezes to a powder consisting of 

 lineK divided metal with between 6 and 10 per 

 cent, ol oxide. More than this, the temperature 

 ;sary to condense the zinc as a liquid depends 

 on the concentration of the vapour, and is lowet 

 the mine dilute it is. Consequently the tempera- 

 ture of the condenser must be near that of the 

 boiling-point of the metal at the end attached to 

 the cry much lower at the oppdsite 



end. In the third pine, the al-vapour is ex- 

 tremi ble to oxidising fluences, e.g. air, 



water-vapour, and even carbon \ide. The 1 hargi 

 must therefore at all stages 1 < n a largi 

 nf 1. 1 bon, since the presence of 1 en o'25 pet cent, 

 of carbon dioxide is sufficient xidise the metal 



in this condition; moreover, volurrn of gas 



carrying; the zinc must be kept mall as possible. 



»554, vi >l. io2 n 



No other common indu trial metal presents this 



combination of cha s, which makes its 



smelting a by no means ward operation. 



These and many othei matt connected with 



the zinc industry are well si ;,, M r . E. A. 



Smith's hook on the subject, whi be warmly 



commended to readers as giving, : n the author's 

 words, "a general surve) of the development of 

 the zinc industry and its present possible 



future position in relation to the va metal 



industries of this country." In spite of the fact 

 thai the ait ol zinc extraction has been carried on 

 in Great Britain lor at least 15,0 years, its I 

 lure is ver\ scanty, ami Mr. Smith's book is there- 

 particularly timely, especially when it is re- 

 membered how gravel) imperilled was the manu- 

 facture of certain munitions of war in this country 

 by the cutting off of zinc supplies in 11)14. Mr. 

 Smith dials successively with 1 be rise and develop- 

 ment of the industry in various centres of produc- 

 tion, the sources of supply and marketing of the 

 zinc ores, their smelting and other methods of 

 extraction — electrothermal and electrolytic — the 

 properties of the metal and its industrial applica- 

 tions as such and in the form of alloys, its com- 

 iii! 1 i.d compounds and pigments, and, finally, with 

 the future of the industr) in this country. As he 

 points out, British smelters in the las! forty years 

 have lagged far behind their rivals in Germany and 

 Belgium. The latter have greatly improved their 

 practice, not only by getting increased extractions 

 from the ore, but also by reducing costs in fuel, 

 retorts, and labour, and this superiority has re- 

 llected itself in the value of their shares as com- 

 pared with those of British companies. 



Mr. Smith's book is well written, well balanced, 

 and accurate. Considering how much work has 

 been done in recent years to render the electro- 

 lytic production of zinc a commercial success, he 

 might with advantage have devoted more than six- 

 pages to this aspect of the industr}', but this 

 appears to the writer the only blemish in a very 

 admirable and valuable book. II. C. H. C. 



THE X ATI: RE OF SOLUTION. 

 The Nature of Solution. By Prof. Harry C. Jones. 

 With a Biographical Sketch by Prof. E. E. Reid 

 and Tributes by Profs. Arrhenius, Ostwald, and 

 Woodward. Pp. xxiii + 380. (London : Constable 

 and Co., Ltd., 1917) Price 125. 6d. net. 

 THE late Prof. H. C. Jones's book on "The 

 J- Nature of Solution " represents undoubtedly 

 his best and ripest work. The scope and outlook 

 of the book are almost unexpectedly wide, in view 

 of the son closely specialised character of 



the author's own researches and of the enormous 

 mas, ol detail which the generosity of the C 

 tnstitutio enabled him to pile up in connection 

 with some three or four problem 



iture of solution. All t' ol 



11 iiii. iti d detail, which compelled him to publish 



from time to time papers summarisii the results 



papers, has been lilt In | : rid in the present 



and the whole Irealr ll of the subject is 



ml satisfying. It is particularly refreshing 



G 



