NOVEMBEB 22, 1907] 



SCIENCE 



711 



the anthracene of coal tar. This discovery, 

 again, was the result of pure scientific work 

 undertaken without reference to its tech- 

 nical importance. The first method of 

 preparation, too, was by a difficult process 

 which was too expensive to be commercially 

 feasible. As soon as the scientific problem 

 had been solved, however, the question was 

 taken up from the commercial standpoint 

 and Perkin soon found an economical 

 method for the manufacture of the dye. 

 At that time large quantities of madder 

 root were raised in Holland and elsewhere 

 for the preparation of alizarin. It was 

 soon found that the dye could be made 

 much more cheaply from anthracene and 

 within a few years the artificial alizarin 

 drove the natural product from the market 

 and the Diiteh farmers were compelled to 

 raise other agricultural products. So im- 

 portant is this dye that the value of the 

 amount manufactured in 1880 is given as 

 $8,000,000. It is estimated that it would 

 have cost $28,000,000 to manufacture the 

 same amount of the dye from madder root. 

 This means that the world saves $20,000,- 

 000 a year in the manufacture of this single 

 dye, an amount that would pay for the 

 maintenance of a good number of chemical 

 laboratories. 



The development of this manufacture 

 was so rapid that by 1873 Perkin and his 

 brother found that it would be necessary 

 to double or treble their factory to supply 

 the demand. Perkin was then only thirty- 

 five years of age and his love of research 

 had survived his seventeen years of experi- 

 ence as a manufacturer. Partly for this 

 reason, partly because he did not wish to 

 assume the responsibility of the larger fac- 

 tory, he sold the works and after that time 

 he devoted himself to scientific research, 

 with distinguished success. The jubilee of 

 the discovery of mauve and the founding of 

 the coal-tar industry was justly celebrated 

 last year as one of the great events of the 



century, but Perkin 's scientific achieve- 

 ments and the way in which he stood for 

 high ideals in research are, I think, of even 

 greater value to the world. 



The manufacture of mauve was quickly 

 successful and after the scientific discovery 

 of the structure of alizarin, commercial 

 production soon followed. "With indigo, 

 the case has been somewhat different. The 

 scientific problem was in itself more dif- 

 ficult and the course of events has illus- 

 trated with especial clearness the difference 

 between the scientific and the technical 

 solution of the same problem. Baeyer 

 began his work on indigo in 1865. During 

 the five years following he prepared a num- 

 ber of important derivatives, which con- 

 tributed much toward the clearing up of 

 the relation between indigo and other com- 

 pounds. In 1870, he found that some of 

 the work he was doing seemed to cover 

 much the same ground as some work which 

 Kekule had undertaken and out of scien- 

 tific courtesy he allowed the matter to lie 

 dormant for eight years. In 1878, as 

 Kekule had published nothing further of 

 importance, Baeyer returned to the prob- 

 lem and in 1880 he obtained a successful 

 synthesis of indigo. With the brilliant 

 success of alizarin in mind patents were 

 taken out, and it was generally expected 

 that the manufacture of the artificial dye 

 would soon become of commercial im- 

 portance. But these hopes of immediate 

 success were not realized. Two principal 

 difficulties were encountered. The original 

 methods of synthesis involved a consider- 

 able number of difficult transformations 

 between the raw material, toluene, and the 

 finished dye, indigo. These transforma- 

 tions required a very large amount of care- 

 ful scientific study before the conditions 

 could be found under which they could be 

 carried out in ways that would be econom- 

 ical of time and material. But when this 

 side of the problem had received a partial 



