Mar. 12, 1874J 



NATURE 



371 



the arsenic and the sulphur, which formerly prevented the 

 burnt pyrites being put to any use, are got rid of, so that 

 what remains is useful in a further stage of the iron 

 manufacture. But with regard to the extraction of the 

 silver, we find how important a knowledge of even deli- 

 cate chemical processes is, in order to allow the extrac- 

 tion to be pursued with advantage. By the ingenious 

 process of Mr. Claudet and Mr. Phillips, it is first of all 

 examined by the nicest chemical means to see the exact 

 amount of silver it contains, by a process rivalling in deli- 

 cacy that which is pursued in laboratory research, and 

 having ascertained exactly the quantity of silver contained 

 in the solution, the exact quantity of extremely expen- 

 sive reagent, iodide of potassium, which is required, is 

 added to it to precipitate the amount of silver : and when 

 the iodide of silver is thrown down the iodine is recovered 

 to be used over and over again, and the silver itself is set 

 free by ineans of metallic zinc, which forms iodide of zinc, 

 thus setting free the silver. In this way, a considerable 

 portion of silver is extracted. 



I mention this as an illustration of the remarkably 

 close association which is every day takmg place between 

 sure chemistry in the laboratory, and manufacturing 

 chemistry in the factory. Now-a-days we have such out- 

 of-the-way bodies, as they were formerly considered, as 

 these different aniline products, as alizarine and chloral, 

 which were formerly barely obvious in the laboratory, now 

 made on a manufacturing scale. On the other hand, we 

 find these different products of estimation, formerly con- 

 fined to the laboratory, are now carried on in the manu- 

 factory, and thereby such an element as silver is produced 

 by processes which are essentially laboratory processes. 

 In this way it happens that we find many improvements 

 in manufacturing chemistry are now produced by men who 

 have obtained a reputation in other r elds. For instance, 

 I need scarcely refer to the names of Hoffmann, Perkin, 

 and Nicholson, gentlemen known as scientific chemists 

 and men of the highest eminence, before their attention 

 was directed to m^nnufacturing operations, and they realise 

 on a manufacturing scale the results of their laboratory 

 experience. In mentioning them, 1 ought not certainly 

 to dissociate from them our le;turer this evening, Mr 

 Field, who was so long and so highly esteemed in purely 

 scientific circles for his admirable researches into a great 

 number of compounds, more especially connected with 

 mineral chemistry, before he devoted his great ability to 

 the elucidation and improvement of the manufacture 

 of aniline dyes, and subsequently to these metamor- 

 phoses of the bodies which we now use for illuminating 

 purposes in the form of paraffine and ozokerit, and also 

 the other candles which are composed of stearic acid, 

 palmitic acid, and so on. 



But while in this way manufactures derive a very great 

 advantagefrom the light thrown on them by purely scientific 

 chemists in one way or another, I do not think we ought 

 to overlook the benefit which pure chemistry derives, on 

 the other hand, from manufacturing operations. I do not 

 mean the mere material gain that purely scientific chemists 

 have enjoyed by the opportunity of examining minutely a 

 great number of bodies, which previously it was almost 

 impossible for them to obtain, but I think they have 

 gained a very much greater knowledge of the especial 

 subject of their studies — 1 mean chemical phe- 

 nomena. We chemists take in our province every 

 change by which one kind of matter becomes me- 

 tamorphosed into another kind of matter, whereby that 

 which was ironstone, for instance, becomes iron, whereby 

 that which was sand, chalk, and soda becomes glass, and 

 which takes place wherever one kind of matter is meta- 

 morphosed into another ; but, after aU, a great number of 

 the metamorphoses which we must study take place in the 

 test-tube and small vessels of similar character ; and we 

 are rather too apt, I say, to shut our eyes to those meta- 

 morphoses which take place on a large scale around us. 



Those changes manifest themselves particularly in 

 two forms. We have those by which the different forms 

 of agricultural produce are furnished us by the vegetable 

 kingdom, and by which they are metamorphosed into the 

 animal kingdom. Here we have one great illustration of 

 industrial chemistry — the chemistry by which crops are 

 produced, and by which stock is fed and flesh is made. 

 This feeding of stock and production of crops is one very 

 large function of industrial chemistry, and I would ven- 

 ture to say that any scientific chemist who devotes his 

 attention entirely to what takes place in the test-tube, and 

 who neglects those changes which are constantly taking 

 place around him, has a very imperfect notioa of the sub- 

 jects which he professes to investigate. And in addition 

 to these changes thus taking place in natural processes, 

 modified to a certain extent by art, we have three other 

 processes which take place on a grand scale, by which 

 from such substances as ironstone we produce metallic 

 iron, from common salt, on the one hand, carbonate of 

 soda, applied to the manufacture of glass and other useful 

 purposes, and by which we provide also chlorine in its 

 different combinations, applicable to so many purposes, 

 more particularly in the preparation of our wearing ap- 

 parel, and in our linen and fabrics of every description. 



I think, then, that when we have the advantage of 

 having these industrial subjects brought under our notice 

 by men like our friend here, who are familiar, on the one 

 hand, with the most recondite points of theoretical che- 

 mistry, and, on the other hand, with the greatest practical 

 achievements which have been obtained in manufacturing 

 chemistry, it will be of immense benefit to those who 

 wish to study chemistry in its pure aspect, as they will 

 see what can be done on a large scale, and what 

 habitually is done, and what perseverance, assisted 

 with chemical knowledge, has obtained for us. It must 

 also be interesting to practical men, by throwing out 

 suggestions capable of improvement in various branches 

 of manufacturing art. I think, then, th it the Society of 

 Arts has really done a very useful work in bringing to- 

 gether men engaged in the purely scientific pursuit of 

 chemistry on the one hand, and, on the other, men who 

 are pursuing the application of the science with a view to 

 the practical good of their kind. I do not know that I 

 need trouble you with any further remarks, but I have 

 attended here this evening with the greatest pleasure, 

 because I feel how much advantage is likely to be derived 

 by all classes of the community by the discussion of these 

 problems which are so interesting to all, and I would ven- 

 ture to say as much in a purely scientific as in a practical 

 point of view. 



x\OTES 



Sufficient attention has not been attracted to the fact that 

 one of the recommendations of the Committee on Scientific In- 

 struction has borne early fruit. Mr. Phillips Jodrell, desirous 

 to promote research in physiology, has attached to the professor- 

 ship of that science in University College, London, an endow- 

 ment of 7,500/. to enable the professor to devote to biological 

 investigation whatever lime is not needed for the discharge of 

 his duties as lecturer. This endowment is accompanied by the 

 further sum oi 500/., to be expended in the purchase of the 

 necessary apparatus. It is difficult to speak in terms sufficiently 

 high of Mr. Phillips Jodrell's intelligent munificence, which, we 

 have no doubt, will bear good fruit. It is gratifying that the 

 recommendations of the Commission have so far had such an 

 excellent result, and we only hope that Mr. Jodrell's handsome 

 example will be largely followed by others who have enough and 

 to spare. 



Our readers will no doubt learn with surprise and regret that 

 M, Alglave, editor of the Revue Scientifique, and Professor of 



