August 27, 1903] 



NATURE 



401 



of biochemistry. The leading idea that the formation of 

 alcohol is a biochemical process depending upon certain 

 organisms, or, as we may now say, upon the products of 

 certain organisms, carries with it, as a necessary conse- 

 quence, the conclusion that the industrial production of 

 alcohol — whether for brewing or spirit distilling, or for 

 the chemical manufacturer — is not an empirical or rule-of- 

 thumb operation depending upon unknown conditions, but 

 a definite chemical change produced in a definite way by 

 a definite organism (yeast), and just as much under control 

 as any other chemical operation. The chemist and the 

 brewer have thus also been brought into association. The 

 recognition that definite chemical transformations can be 

 effected by microscopic forms of life which resulted from 

 Pasteur's studies in wine and beer has had such far-reaching 

 consequences that it is impossible to overestimate the im- 

 portance of this work for the well-being of humanity. I 

 should be encroaching upon the domain of Prof. Sims Wood- 

 head were I to do more than remind you of the growth of 

 that modern science — the most humanitarian of all the 

 sciences — bacteriology, out of this fundamental conception. 

 Keeping to the main topic of industrial results, one outcome 

 has been, as I have said, to bring the operations of the 

 brewer under scientific control. The organism, the yeast 

 introduced into the vat to induce fermentation, must under- 

 go careful microscopic e.xamination to see that it contains 

 no deleterious organisms, i.e. no organisms which would 

 give rise to products other than alcohol. The water used 

 by the brewer must be analysed to ascertain whether it 

 contains the necessary mineral constituents for the nourish- 

 ment of the yeast, because this plant is subject to the same 

 conditions of growth as any other plant. Instead of obtain- 

 ing its carbon from carbon dioxide, however, it can utilise 

 sugar for this purpose, and it decomposes the sugar into 

 carbon dioxide and alcohol in the way indicated. 



The recognition of yeast as a vital chemical reagent 

 which is apt to contain impurities in the form of wild or 

 stray organisms which may damage the contents of the 

 brewing vat, has led further to the introduction of the 

 process of brewing by what is known as " pure culture 

 yeast." This industry, of which the home is chiefly on 

 the Continent, depends on the use of a yeast cultivated 

 in the first place from a single cell of some particular 

 *t)l?cies or variety or race by methods similar in principle 

 to those adopted by the bacteriologist, the cultivation being 

 carried on from generation to generation in carefully pre- 

 paired solutions containing the necessary nutrient materials, 

 sugar, nitrogenous matter, mineral salts, &c., and previously 

 sterilised by heat so as to destroy every other form of life. 

 The brewer can now be supplied,' as the outcome of a series 

 of brilliant investigations by Hansen, of Copenhagen, to 

 whom he is indebted for this purification of the biological 

 foundation of his industry, with a cultivated yeast as pure 

 in strain as a pedigree horse or a particular breed of dog 

 —a yeast which, by virtue of its purity, can be depended 

 on for giving constant results in the brewing vat. This 

 IS another illustration of the relationship between research 

 and industry. 



Consider, in the next place, the sugar which the yeast 

 decomposes by virtue of its zymase. In an ordinary brew- 

 ing operation the liquor which is fermented is not supplied 

 in the first place with sugar as such, but the starch con- 

 tamed in the barley grain is ultimately broken down, as 

 chemists say, into sugar by virtue of certain processes 

 which I cannot stop to explain. But the broad fact is that 

 yeast cannot feed upon starch, but onlv upon sugar, and, 

 in fact, only upon certain kinds of sugars, and the starch 

 which is stored up in the barley is the raw material which 

 ultimately supplies the necessary kind of sugar. So that 

 starch, which, as you know, is a substance very widelv 

 distributed in the vegetable kingdom, can be extracted if 

 necessary from the seeds or tubers which contain it, and con- 

 verted into sugar by chemical processes, and then used for 

 the production of alcohol. An important industrv is flourish- 

 ing in Germany at the present time for the production of 

 alcohol from potato-starch. In Berlin a few weeks ago we 

 were shown over a large establishment entirely devoted to 

 the fermentation industries, and potato spirit and other pro- 

 ducts from the potato were the most conspicuous features 

 of the exhibition. Now alcohol is a substance of great 

 NO. 1765, VOL. 68] 



importance for chemical industry in many directions, and 

 its inflammability makes it valuable as a fuel, so that the 

 problem of the cheap production of alcohol is worthy of the 

 serious attention of investigators. It is interesting to con- 

 template the period when our natural sources of fuel, coal 

 and petroleum, are all exhausted, and when we may have 

 to fall back upon the vital activity of a lowly form of 

 vegetable life to supply us with liquid fuel. Scientific re- 

 search has helped here, also, to call a new industry into 

 existence, because the cost of alcohol, like that of any other 

 chemical product, is obviously dependent upon the yield 

 i.e. upon the quantity obtainable from a given weight of 

 raw material. I must claim your indulgence while I trace 

 in brief outline one of the most beautiful of the modern 

 industrial developments of the principles of fermentation. 



It had long been known that in Java an alcoholic 

 beverage, known as arrack, was prepared by fermenting 

 molasses with a peculiar ferment prepared by a special 

 process from rice. From what has been previously said, 

 vou will understand that the starch contained in rice is 

 nor as such, available for direct alcoholic fermentation. 

 A detailed scientific investigation of the starch-fermenting 

 materials used in Java and elsewhere in the Far East has 

 revealed the fact that these ferments owe their activity to the 

 joint action of two out of several different organisms which 

 are contained in them. One of these is a mould fungus 

 which has the property of saccharifying starch, i.e. breaking 

 it down into sugar, and thus rendering it available for the 

 growth of the other organism, which is a yeast capable 

 of exciting alcoholic fermentation in the usual way. Now 

 the principle revealed by the scientific study of these eastern 

 ferments has been developed into an industrial process for 

 producing alcohol from starch of any origin, such as from 

 maize, rice, potato, &c. The operations, in the briefest 

 possible terms, consist in saccharifying the prepared starch 

 by a pure culture of mould fungus, and then fermenting 

 bv means of yeast. The problem of increasing the yield 

 of alcohol has thus been solved ; not only is the spirit 

 obtained in more concentrated form, but the actual per- 

 centage of alcohol furnished by a given weight of starch-, 

 is much greater than has ever been obtained by any of the 

 older processes of fermentation. 



I have left but little time for dealing with an industry 

 with which I have had long personal connection — the manu- 

 facture of colouring matters and other products from coal 

 tar. The relations between scientific research and this in- 

 dustry are so intimate, and are so frequently referred to in 

 public, that it has become a kind of stock example for the 

 use of those who wish to emphasise the interdependence of 

 science and industry. The history of this industry, more- 

 over, is particularly instructive from our present point of 

 view, because it originated in this country in 1858 and 

 flourished here for a period of about twenty years, and then 

 began to decline. The chief centre of activity for the pro- 

 duction of coal tar products at the present time is Germany, 

 where there are six large factories and a number of smaller 

 ones. The aggregate capital of the six large factories 

 amounts to some 3,000,000/., and they give employment to 

 about 20,000 people, including chemists, engineers, clerks 

 and travellers, dyers and draughtsmen, workmen, &c. 

 These large firms pay dividends varying between 5 and 25 

 per cent, upon their capital. The total value of the tar 

 products manufactured in Germany exceeds 10,000,000/. 

 annually, and she supplies by far the largest proportion 

 of the dye-stuffs used throughout the world. When, in 

 1886, I proclaimed our approaching fate with respect to 

 this industry, I found that we were then using about 90 

 per cent, of German and other foreign colouring matters 

 in this country, and my friend, Prof. Arthur Green, of the 

 Yorkshire College, finds that things are in about the same 

 state at the present time. 



The coal tar colour industry arose, in the first place, from 

 an observation made by Dr. W. H. Perkin in 1856 in the 

 course of a research having for its object the synthesis of 

 quinine. He did not succeed in producing the alkaloid, , 

 but he noticed that aniline, when oxidised, gave a colour- 

 ing matter, which he manufactured and introduced under 

 the name of " mauve," and so laid the foundations of an 

 industry which has developed to its present colossal dimen- 

 sions. The art of the dyer and calico-printer has been 



