262 Obituary Notices of Fellows deceased. 



accomplished ; its opening words, indeed, seem to lay out the course of 

 his life's work. " Our knowledge," it begins, " concerning that depart- 

 ment of organic chemistry which embraces the colouring matters is of 

 the most imperfect kind. Though many other branches of organic 

 chemistry have been so thoroughly and accurately investigated that 

 little or nothing remains to be known concerning them, this may be 

 called an unexplored field." Into this unknown country Dr. Schunck 

 penetrated, and carried out his explorations with a perseverance and 

 an experimental skill which rapidly won for him a permanent reputation 

 among chemists. 



In 1846 Dr. Schunck published his earliest work on the colouring 

 matter of madder, a subject he made his own by investigations 

 carried on for many years. Alizarin, the colouring principle obtained 

 from madder, has been used as a dye from the earliest times ; the 

 plant was cultivated by the Eomans. Pliny says, " The madder of 

 Italy is most esteemed." "It is a plant," he adds, "little known 

 except to the sordid, and this because of the great profits arising from 

 its employment in dyeing wool and leather." From Pliny's time the 

 cultivation of madder has been an important branch of agriculture in 

 Italy and France. Forty years ago the madder annually imported 

 into England was valued at 1J million sterling. 



Colin and Robiquet first attacked the chemistry of madder, and 

 succeeded in 1827 in separating the crystallized substance alizarin. 

 Other chemists next described two colouring matters obtained from 

 madder, and Shiel in 1846 analysed and assigned formulae to these 

 substances. In 1848 Dr. Schunck showed that the colouring matter 

 did not exist in the root when freshly taken from the ground, but was 

 formed after the death of the plant. He showed that this was the 

 result of a fermentative change brought about by a material contained 

 in the root itself. He proved that the crystallised alizarin was 

 chemically the same body as the yellow flocculent precipitate thrown 

 down from solutions. His analyses of alizarin and the other con- 

 stituents of the root first showed their chemical nature and paved the 

 way for the researches of Graebe and Liebermann, who synthesised 

 alizarin. This artificial preparation of alizarin was soon followed by 

 Perkin's discovery, which has made alizarin a commercial product and 

 superseded the growth of madder. 



In 1876 Dr. Schunck discovered anthraflavic acid, which he sub- 

 sequently isolated from the bye-products accumulated in the manu- 

 facture of artificial alizarin, and by fusing this acid with potash he 

 obtained flavopurpurin. In conjunction with Roemer he published a 

 series of papers on purpurin and its congeners, and in 1893, in con- 

 junction with Marchlewski, he obtained another colouring matter 

 rubiadin (a dihydroxy-methyl-anthraquinone) from the madder root. 



