August 27, 1903] 



NATURE. 



399 



It is obviously impossible in view of the enormous range 

 of industry in which chemistry is directly or indirectly con- 

 cerned to do more on the present occasion than take a 

 cursory glance at a few of the more striking cases illustra- 

 tive of the connection between research and industry. As 

 .1:1 example of the creation of an industry through research 

 directed towards a special end, attention may be directed 

 to the manufacture of optical and other glass at Jena. The 

 liistory of this branch of manufacture, and the results 

 achieved, have been fully described by Dr. Hovestadt in 

 a work published three years ago, and of which a transla- 

 tion, by Prof, and Miss Everett, has been recently pub- 

 lished in this country. I must refer you to this work for 

 full particulars. The physical requirements to be complied 

 with in order to produce the most perfect glass for the 

 construction of lenses for optical instruments had long been 

 known, and many attempts had been made to realise these 

 conditions in practice. A visit to the international ex- 

 hibition of scientific apparatus in London in 1876 led Prof. 

 Abbe to direct attention once again to the fact that the 

 future perfection of the microscope lay with the glass- 

 maker, and in 1881 he, in conjunction with Schott, com- 

 menced a set of experiments having for their object the 

 production of a series of glasses of known composition, the 

 optical properties of which were concurrently determined 

 by measurements made by Prof. Abbe. The experimental 

 meltings were enlarged in scale the following year, and an 

 experimental laboratory established for the continuation of 

 th-i work at Jena. A chemist was added to the staff, and 

 thus there were cooperating in this industrial research a 

 glassmaker, a chemist, and a physicist. Before the end of 

 .1883 the results had been so far successful that the Jena 

 laboratory was in a position to make known to the world 

 the processes for the " rational manufacture of optical 

 glass." At this stage the experimenters were persuaded to 

 put the results of their labour into practice, and the instru- 

 ment makers, Messrs. Zeiss, having joined in, the Jena 

 glass factory for producing optical glass on the commercial 

 scale was established towards the end of 1884. In the first 

 catalogue published by the Jena Works in 1886, we are told 

 that forty-four optical glasses, nineteen being new in com- 

 position, were included. By 1888 ■ the undertaking had 

 been so successful that a supplementary catalogue was 

 issued containing twenty-four additional glasses, of which 

 thirteen were new, and in 1892 a second supplement 

 announced the manufacture of eight more kinds of glass, of 

 which six were new. Consider what this piece of work, 

 prompted by science, fostered by the State, and carried out 

 by a university professor in conjunction with a technologist 

 has done for German industry. In the early stages of the 

 experiments, before Commercial results had been obtained, 

 the experimenters were subsidised by the Prussian Educa- 

 tion Department and by the Prussian" Diet with a wise fore- 

 thought which subsequent events have amply justified. 

 Need I remind those who have come here to hear about 

 bacteriology from Prof. Sims Woodhead how that science 

 has advanced pari passu with the perfecting of the micro- 

 scopic objective? The Zeiss instruments are now world- 

 renowned, for it is obvious that a command over the pro- 

 cesses for making glass with any particular optical proper- 

 ties that might be desired would enable the instrument 

 maker to produce lenses suitable for. other purposes, such 

 as telescopes, field-glasses, photographic cameras, &c. I 

 am afraid to dwell too much upon the perfection of the 

 lenses of the Jena instruments because I lav myself open 

 to the charge of holding a brief for a particular firm. If 

 you want to know more fully what this optical glass in- 

 dustry has done for Germany, I refer you to the report 

 on instruments of precision published in connection with 

 the German exhibit at the Paris International Exhibition 

 of iqoo. As a further outcome the study of the properties 

 of glasses of known composition in connection with their 

 thermal and electrical behaviour has led to the manufacture 

 of glass especiallv suitable for making thermometers, as 

 also for electrical insulation, for the construction of the 

 vacuum tubes used for producing Rontgen rays, and for 

 the vessels employed in chemical laboratories. In brief, 

 the manufacture of the finer kinds of glass has been placed 

 upon a strictly scientific footing as the outcome of scientific 

 research. 



NO. 1765, VOL. 68] 



The next illustration, which I propose to make use of 

 refers to the applications of chemistry to agriculture. The 

 growing plant, as you are aware, requires food for its 

 growth just as much as the growing animal. Take an 

 extreme case, and consider the size and weight of an oak 

 tree as compared with the acorn from which it arose. This 

 enormous accumulation of matter represents the assimilation 

 of gaseous food in the form of carbon dioxide from the air 

 through the leaves, and of water and nitrogenous and other 

 mineral matter through the roots. It was the great 

 German chemist Liebig who first established this broad 

 principle of plant growth, by systematic experiments upon 

 various crops, and his results were given to the world ii. 

 a work published in 1840, the English edition, edited by 

 Lyoti Playfair (afterwards Lord Playfair), bearing the title 

 " Organic Chemistry in its Applications to Agriculture and 

 Physiology." Perhaps few students consult this work now, 

 but it was, strictly speaking, epoch-making on its appear- 

 ance, because it brought the chemist into direct relationship 

 with the farmer, and the consequence has been an enormous 

 increase in the food-raising capacity of the soil. It is not 

 necessary to inquire closely here into the motives that 

 prompted Liebig's investigations — whether his work comes 

 under the category of scientific researches directed towards 

 a practical end, or whether he begaii with a desire of 

 ascertaining abstract truth in the first place, and then found 

 that his results were capable of practical application. It 

 is quite immaterial from the present point of view how this 

 work originated, because we are considering only the bear- 

 ing of the results .upon industry. It is evident that if a 

 growing plant requires certain elements, such as potassium, 

 sodium, phosphorus, nitrogen, calcium, magnesium, 

 sulphur, chlorine, iron, &c., and. if the soil by previous crops 

 has been ex,hausted of some of these elements, it will not 

 b.3 possible to raise subsequent crops on this impoverished 

 soil unless the necessary elements are supplied. In other 

 words, the requisite elements must be added, and added 

 in the form of compounds' which the plant can make use 

 of. Thus the great industry of crop-raising, and as con- 

 nected therewith the feeding of farm stock, was shown 

 to depend ultimately upon the chemical composition of the 

 soil, and the manufacture of artificial manures or fertilisers 

 has been the practical outcome of Liebig's researches. 



Let us consider, further, the industrial results so far as 

 these have influenced chemical manufactures. Prof. 

 Warington can tell you all about the agricultural results. 

 The elements which are most likely to fail, and which, in 

 fact, have generally to be supplied, are potassium, phos- 

 phorus and nitrogen, excepting, of course, in the case of 

 those particular leguminous plants which have developed a 

 special means of fixing atmospheric nitrogen. Chemistry 

 having thus been called upon to supply the agriculturist 

 with compounds containing potassium, - phosphorus and 

 nitrogen, the first development which may be ascribed to 

 Liebig's influence is the Stassfurt salt industry in Prussia, 

 where immense deposits of salts containing potassium were 

 known to exist. Similar deposits are found in Anhalt. 

 The mining of these salts was commenced in i860, and 

 has proved an immense source of Wealth to Germany, the 

 total value of the Stassfurt and Anhalt salts produced down 

 to 1890 being estimated at 11,500,000!., and since that time 

 the output has gone on increasing from year to year. It 

 is not necessary to weary you with statistics, but it is im- 

 portant to note how the demand for potassium salts for 

 agricultural purposes has given rise to a great industry, 

 for the natural salts, consisting chiefly of carnallite, a 

 double chloride of potassium and magnesium and kainite, 

 a double sulphate of potassium and magnesium with mag- 

 nesium chloride, have to be submitted to various processes 

 in order to separate the constituents, and the Stassfurt salt 

 factories are now supplying Germany, as well as exporting 

 laige quantities of potassium chloride and sulphate, mag- 

 nesium chloride and sulphate, potassium carbonate, caustic 

 potash, &c. 



In a similar way the demand for phosphates has given 

 t ise to the utilisation of every available source of these com- 

 pounds. Calcium phosphate is found as the mineral 

 apatite, a double calcium phosphate and chloride or fluoride 

 occurring in vast deposits in America, and also in a less 

 definite ^orm in Canada, the West Indies, France, Belgium^ 



