February 23, 1911] 



NATURE 



561 



activity in Germany. It stands no longer in fear and 

 trembling of the complicated constituents of the living 

 organism. I shall demonstrate this fact by discussing the 

 three classes of substance predominating in organic life : 

 the fats, the carbohydrates, and the proteins. The 

 svnthesis of fats was effected so far back as two genera- 

 tions ago by M. Berthelot in Paris. The first synthetical 

 carbohydrates — grape sugar, fruit sugar, &c. — saw the 

 light twenty years ago in Wurzburg ; and the methods for 

 the synthetical building up of albuminous substances have 

 been worked out during the last ten years in the laboratory 

 of the University of this city. I am therefore able to 

 show vou one of these products. It is the most compli- 

 cated substance ever evolved by synthesis, and has so long 

 a name that I do not venture to pronounce it here. The 

 amount is certainly small, and, as you will perceive later, 

 the beakers and flasks of the scientific investigator are 

 minute when compared with the vats employed by the 

 chemical manufacturer. This relative difference in size is 

 also borne out by the comparative wealth of these two 

 classes of men. This synthetical protein, like the prepara- 

 tion of Dr. Hahn, is anvthing but cheap. The starting 

 materials for its synthesis cost about 50/., and the labour 

 involved in its preparation must be estimated at even a 

 higher figure. It has therefore not as yet made its appear- 

 ance on the dining-table. It is, in fact, nothing but a 

 chemical curiosity. But you must bear in mind that what 

 is to-day a curiosity may to-morrow be of the greatest 

 value. Chemistry affords numberless illustrations of this 

 statement. 



Through such things as these proteins, carbohydrates, 

 and fats, organic chemistry is brought into close touch 

 with the biological sciences ; for the entire metabolism in 

 the living organism is merely a sequence of chemical trans- 

 formations which these substances undergo. Chemistn.- is 

 thus called upon to partake in the solution of the great 

 riddles of life : nourishment, growth, reproduction, 

 heredity, age, and the manifold pathological disturbances 

 of the normal state. It is not surprising that the keenest 

 activity e.iists in these interesting fields of work, and we 

 may safely hope that provision will be made for biological 

 research in the new Kaiser-Wilhelnx institutes. 



The example given by the magnificent institute here in 

 Berlin for the study of the problems of the industries con- 

 nected with fermentation, in which the results of scientific 

 research meet the practical requirements of brewers and 

 distillers, serves to show how fruitful can be the collabora- 

 tion of biologists and chemists. This institute has contri- 

 buted its share to the small exhibition here this evening by 

 a series of beautiful mould cultures and yeast preparations. 



Moreover, chemical and many other industries have 

 derived great benefit from organic chemistry. A few- 

 examples from recent times will illustrate this fact. 



The most widely distributed of all the carbohydrates is 

 cellulose, of which cotton and linen are entirely composed, 

 and which is the chief constituent of wood and plant 

 fibres. And what a variety of articles is nowadays manu- 

 factured from cellulose ! Paper, collodion, celluloid, 

 photographic films, smokeless powder, artificial silk, 

 artificial hair, artificial leather. 



Paper, in this era of paper, is not a substance which 

 justifies its exhibition here ; the same may be said of 

 celluloid and collodion. I have not brought here samples 

 of smokeless powder and the other high explosives derived 

 from cellulose, as the Ministn.- of Education seems a place 

 far toKV peaceful for their exhibition. But you see before 

 you artificial silk and horse-hair and films in diverse and 

 magnificent array. These come from the works of Furst 

 Guido von Donnersmarck ; and not to omit mention of 

 his competitors, I here show you some photographic films, 

 manufactured by the Berlin Anilinfabrik, which, unlike 

 the ordinary variety, burn only with the greatest diflficuliy. 

 All these products have been prepared by ingenious com- 

 binations of chemical and mechanical processes. To dispel 

 any false impressicKi, I must tell you that artificial silk 

 and hair, in spite of their striking similarity, are of totally 

 different composition from the natural products, which are 

 not derived from cellulose, but belong to the class of 

 proteins. 



The magnificent colours ^ with which these artificial tex- 



1 The first, " mauvine," was prepared by the late Sir William Perkin in 

 the year 1856 and manufactured at Greenfbrd. — Tr. 



NO. 2156, VOL. 85I 



tures are so beautifully dyed are, of course, the work of 

 organic chemistry. These belong to the family of synthe- 

 tical co>al-tar dyes. This subject is to-da\- so large that 

 complete half-yearly courses of lectures are delivered upon 

 it at the universities. Hundreds of such dyes are on the 

 market, and the value of the dyestuffs produced in 

 Germany, the majority of which are exported, approxi- 

 mates to fifteen millions of pounois sterling. 



Of all these dyes I shall only mention s>-nthetical indigo, 

 because this substance was the most difficult of all to 

 synthesise, and on the other hand was a great commercial 

 success. This beautiful crystalline preparation, purified by 

 sublimation, hails from the Badische Anilin- und Soxia- 

 fabrik. It is also manufactured by the dje factory at 

 H6chst-am-Main. 



This synthetical product is not only much purer in com- 

 position and colour than the natural dyestuff, but alk> 

 considerably less expensive. On this account, the cultiva- 

 tion of the indigo plant in India has diminished to one- 

 sixth of the original extent, and will, to all appearances, 

 soon disappear altogether.' \Vo)o>llen and cotton goxwis are 

 now dyed with German indigo even in Asia, to which ccvn- 

 tinent a quantity of indigo worth no less than i,90X),ooo/. 

 was exported in the year 190)9. 



While on this subject, I may refer to the two most 

 important colouring matters of animal and vegetable life, 

 chlorophyll and haemoglobin. The former plays an 

 important part in the chemical process upon w^hich all lif-e 

 depends — I refer to the conversion of the atmospheric 

 carbon dioxide into sugar, which takes place in green 

 leave* under the influence of sunlight. The red pigmen: 

 in the blood fulfils in our own bodies the important func- 

 tion of transporting the oxygen from our lungs to the 

 tissues, thus rendering possible that process of combustion 

 which forms the basis of our bodily and mental strength. 



I here show to you two specimens o>f pure chlorophyll, 

 one of which is crystalline. I owe these rare preparations 

 to Prof. R. Willstatter, of Zurich, who of recent _vear> 

 has been studying this colouring matter with remarkabl> 

 successful results. Haemoglobin has also lately been 

 thoroughly investigated in Stuttgart and in Munich, and 

 the remarkable conclusion has been drawn from these 

 investigatiotis that chlorophyll and haemoglobin are closely 

 related. This fact thus denotes a species of consanguinity 

 between the animal and vegetable kingdoms. This must, 

 however, be of great antiquity — that is to say, to dat-? 

 from remote times, when the animal and vegetable 

 kingdoms were as yet not distinct. 



Of greater commercial importance than the coal-tar dyes 

 is indiarubber. Its consumption is continually increasing, 

 and is estimated at some 70,oox) tons yearly, an amount 

 corresponding in price to abonit thirt>-five millions of 

 pounds. You can therefore readily understand that th:~ 

 subject has attracted the attention of synthetic chemists, 

 and for the last nine months one has heard, even in public, 

 of attempts to prepare synthetical indiarubber. In fact, in 

 August, 1909, Dr. F. Hofmann and Dr. C. Coutelle, 

 chemists to the Elberfelder Farbenfabrik, succeeded in 

 devising a practical proxress for its synthesis. The start- 

 ing material is a volatile, mobile, and colourless liquid 

 termed isoprene," which in turn can be readily synthesised 

 from even simpler substances. 



This liquid is converted into indiarubber merely on heat- 

 ing in closed vessels. Here you see a sealed glass tube 

 which was originally filled with this mobile liquid isoprene, 

 but now, after heating, contains a jelly-like mass o*^ 

 synthetical indiarubber. When thus prepared on a larg 

 scale, it is somewhat denser and of a light yellow colour, 

 as you see from this preparation. That this proxluct i- 

 reallv indiarubber has been definitely established by the 

 scientific investigations of Prof. Harries in Kiel, a high 

 authority on this subject, who has since independently 

 devised another process for the same purpose. 



When synthetic chemistn.* has once taken possession of 

 such a field, it is not confined to the particular proxiuct 



1 The recent work of Bloxam and his collaborators hss demonstrated the 

 possibility of recovering: from the leaf a yield of indigo increased to such a 

 degree that the cost of production is certainly no more than that of the 

 sj-nthetical product. Furthermore, the natural indigo is stated by some 

 authorities to possess certain benign impurities which render it more suitable 

 for dyeing purposes. — Tr. 



* First shown to yield indiarubber in 1S92 by Sir William Tilden {Ckem. 

 iVV»*, IxT., 265). — Tr. 



