July 6, 1917] 



SCIENCE 



furnish him with the necessary financial 

 assistance. It was a new thing under the 

 sun and it is fascinating to read of the diffi- 

 culties met and overcome in developing the 

 industry of the coal-tar dyes. The benzene 

 which is now separated from coal-tar to the 

 amount of thousands of tons annually was 

 not to be had as a definite product and it 

 was necessary to invent the machinery and 

 apparatus for carrying out on a large scale 

 operations which, hitherto, had been tried 

 only in test-tubes. Even when the new dye 

 had been made, the dyers, who were accus- 

 tomed only to vegetable dyes, could not use 

 the product and Perkin had to go into their 

 dj'ehouses and teach them how to handle 

 the matei'ial. All of these difficulties were 

 finally overcome and a successful founda- 

 tion was laid for a great industry, which in 

 less than a generation revolutionized the 

 artistic beauty of our wearing apparel. 



A few years later two German chemists 

 solved the riddle of the structure of aliza- 

 rin, the coloring matter of madder root, 

 and showed that the dye could be made 

 from the anthracene of coal tar. They did 

 not, however, put the production of the ma- 

 terial on a commercial basis and here, 

 again, it was "William H. Perkin who 

 worked out the economic details of manu- 

 facture in his factory. 



With such a beginning it would have 

 seemed that England must be the leader in 

 the manufacture of artificial dj'cs, but long 

 before the end of the nineteenth century 

 Great Britain had lost all her initial ad- 

 vantage and Germany was preeminent in 

 the production of synthetic colors. 



"When we look foi- the reason for this sur- 

 prising result we find it almost entirely in 

 the laboratories founded on Liebig's ideal 

 — laboratories where students learned the 

 chemistry already known, it is true, but 

 where, much more than that, and as their 

 prime object, teachers and pupils gave 

 their energies intensely and incessantly to 



the development of an ever-changing sci- 

 ence. Young men trained in such an at- 

 mosphere proved to be the very ones who 

 could solve the varied problems of an in- 

 dustry which is so intimately connected 

 with investigations in pure science. In ad- 

 dition to the supply of trained chemists fur- 

 nished by the universities there grew up a 

 most intimate connection between the uni- 

 versity laboratories and the factories where 

 dyes were made. An illustration will help 

 to make this clear. Kekule, one of the men 

 who worked with Liebig in Giessen, pro- 

 posed his theory of the structure of benzene 

 in 1865. This has become, perhaps, the 

 most important single thought guiding the 

 work of the color-chemists even to the pres- 

 ent day. Baeyer, who had studied with 

 Kekule, took up, in the same year, some 

 work on isatin, an oxidation product of 

 indigo. He tells us with what pleasure he 

 had spent for a piece of indigo a birthday 

 present of two thalers, given him when he 

 was thirteen, and with what a feeling of 

 reverence he drew in the odor of orthoni- 

 trophenol while he was preparing isatin 

 from it by the directions which he found in 

 an organic chemistry. 



After working upon isatin and other de- 

 rivatives of indigo for four years with good 

 success Professor Baeyer dropped the sub- 

 ject for eight years because his former 

 teacher Kekule published a paper in which 

 he announced that he was attempting a 

 synthesis of isatin. It was evident that 

 Kekule did not succeed and in 1877 Baeyer 

 felt justified in taking up the subject again. 

 Three years later he discovered a synthesis 

 of indigo which was of sufficient promise 

 for a patent and the Badische Anilin Soda 

 Fabrik began at once an attempt to put the 

 synthesis on a manufacturing basis. But a 

 successful synthesis in the laboratory is 

 very different from successful production 

 in a factory. The chemists of the factory 

 worked over the process from every pos- 



