July 5, 1877] 



NA TURE 



181 



the growth of scientific knowledge. The facts discovered 

 in the laboratory have been turned to account in the 

 alkali work, and the theories of the chemist have not un- 

 frequently received confirmation at the hands of the 

 manufacturer. Conversely, the wants of the manufacturer 

 have hastened the discovery of fresh facts, and the success 

 or failure in the application of these facts on the large 

 scale has reacted beneficially upon the advance of 

 chemical theory. In 1750 sulphuric acid was manufac- 

 tured by distilling sulphate of iron in earthen vessels 

 luted to glass receivers. The destruction of plant obliged 

 the manufacturer to adopt a better method. The chemist 

 supplied him with the facts : Nitre and sulphur when 

 burnt together produced sulphuric acid. The manufacturer 

 supplied the mechanical means for realising this process on 

 the (comparatively) large scale. Soon after this time 

 Scheele discovered chlorine ; the manufacturer, acting on 

 the experiments of the chemist, turned to account the fact 

 that chlorine readily combines with hydrogen. But the 

 impulse thus given to the bleaching trade necessitated a 

 corresponding advance in the manufacture of sulphuric 

 acid. The chambers in which the nitre and sulphur were 

 burnt were enlarged, improvements were adopted, and the 

 price of the acid decreased while the consumption in- 

 creased. 



In more modern times we see the" need of a cheaper 

 method for manufacturing chlorine, giving rise to the 

 successful process of Weldon, a process based upon 

 strictly experimental laboratory data, and to the hitherto 

 not so successful process of Deacon. We see the failure 

 of the latter process inducing its discoverer to extend his 

 researches, and as a consequence chemical science is 

 enriched with a valuable paper which throws consider- 

 able light upon the general principles of chemical 

 dynamics. 



While the history of the alkali trade illustrates the 

 benefits conferred upon manufactures by science, and the 

 requital made to science by manufactures, it also forcibly 

 illustrates the uses which to-morrow may bring for the 

 waste products of to-day. 



The monopoly granted by the King cf Sicily to one 

 firm in the exportation of sulphur obliged the manufac- 

 turers of oil of vitriol to have recourse to some other 

 source of sulphur. The introduction of pyrites led to the 

 accumulation of burnt ore, and this again to Henderson's 

 method for extracting copper, a method which, whether 

 considered chemically or commercially, has proved most 

 successful. The hydrochloric acid sent out from the 

 chimney of the alkali works has, since 1863, been almost 

 wholly condensed, and from this once wasted acid im- 

 mense quantities of bleaching powdei are now manufac- 

 tured. The acid liquors from the manganese still, although 

 rich in manganese, were formerly sent into the nearest 

 stream, thus causing at once a loss to the manfacturer 

 and a nuisance to the neighbourhood. Now, however, 

 these liquors are turned to use, the nuisance is abated, 

 and the manufacturer is enriched. 



But if one is to acquire a just idea of the immense 

 dimensions, and of the importance of the alkali trade 

 from a commercial, chemical, or general point of view, 

 one must learn in detail the history of the manufacture, 

 the development of the processes which gather round 

 the alkali trade as their centre, and the connections 



ivhich subsist between the practical carrying out of 

 the manufacture and the general principles of chemical 

 science. Such a knowledge may be obtained from the 

 work before us. Mr. Kingzett gives a clear and succinct 

 account of the rise of the alkali trade and of the present 

 state of the manufacture. Notices, sufficiently detailed 

 for the purposes of the general reader, of all the recent 

 improvements are introduced. The allied trades, espe- 

 cially the bleaching powder and soap manufactures, are 

 described. 



The book necessitates a general knowledge of chemistry 

 on the part of the reader, inasmuch as processes are every- 

 where referred to their fundamental chemical principles. 

 He who wishes for a rule of thumb acquaintance with the 

 alkali manufacture will certainly find the information 

 given in this work beyond his scope. On the other 

 hand, the man who, having a general knowledge of 

 chemistry, really wishes to learn how chemical facts are 

 turned to account in manufactures, and also how me- 

 chanical difficulties are overcome, cannot do better than 

 study — not read only — the work before us. 



The chemical manufacturer also may gain from this 

 ivork a more extended knowledge of his trade, and he 

 may receive many hints, which, if he be of an inventive 

 turn of mind, he may some day turn to account. The 

 author has evidently endeavoured to treat the subject 

 from the standpoint of the scientific manufacturer, and 

 we think he has very fairly succeeded. 



Full details of the more modern improvements of Har- 

 greaves, Mactear, and others in the manufacture of alkali 

 are given. The Weldon process for manufacturing bleach 

 is described minutely, the improvement suggested by Mr. 

 Weldon, whereby loss of calcium chloride would be 

 avoided, is mentioned, and its utility is pointed out. 



Of course there are parts of the book which it appears 

 to us admit of improvement. The introduction of an index 

 would add to the value of the work. Might we suggest 

 to Mr. Kingzett that it would be well to re-write the pre- 

 face, and generally those portions of the work in which 

 he indulges in philosophismg ? The book begins with 

 a platitude : " The wealth of a nation may be said to be 

 indicated by the magnitude of its commerce." It closes 

 (the last chapter is purely statistical) with a poor simile : 

 " Life may be compared to a spectrum with its bright and 

 dark lines." 



M. M. Pattison Muir 



OUR BOOK SHELF 



River Terraces. By Col. George Greenwood. (London : 

 Longmans and Co.) 



For somewhere about fifteen years no name occurred more 

 frequently in the geological correspondence of our maga- 

 zines and newspapers than that of " George Greenwood, 

 Colonel," and no letters carried with them a more marked 

 individuality than those to which that name was appended. 

 They never betrayed any doubt or hesitation, but made 

 merry over the doubts and difficulties of other and more 

 experienced observers ; they showed in vigorous language 

 that in so far as a correspondent agreed with their author, 

 he was right, that in so far as he differed he was wrong. 

 Fathers in science like Lyell and Darwin, as well as 

 striplings, not yet emancipated from geological long- 

 clothes — one and all needed instruction and correction at 

 the hands of the enthusiastic Colonel. He spoke of the 



