RESEARCH AND THE COAL-TAR DYE INDUSTRY 239 



At the request of the trustees, Liebig recommended one 

 of his pupils, A. W. Hofmann, as a suitable candidate for the 

 position of Professor of Chemistry, and in 1845 ne came to 

 England to undertake the task of organising the study of 

 chemistry at the College. 



If Hofmann had possessed foreknowledge of the importance 

 to which the coal-tar industry was presently to attain, he 

 could scarcely have undertaken research work more directly 

 calculated to lay its foundations. 



Whilst at Giessen Hofmann had undertaken, at Liebig's 

 suggestion, an investigation of the composition of coal-tar, 

 and upon his arrival in London he continued the work and put 

 one of his students, Charles Mansfield, to examine the hydro- 

 carbons in tar, which resulted in the isolation of benzene and 

 various other bodies in quantities which showed coal-tar to be 

 a convenient source for such compounds. 



At the same time a second student, William Henry Perkin, 

 was set to investigate another tar hydrocarbon, " parana- 

 phthalene " (or, as it is now termed, anthracene), which, though 

 not affording great results at the time, gave Perkin most 

 valuable experience, which he turned to good account a decade 

 later in the synthesis of alizarine. 



At the same time Hofmann himself was investigating an 

 oily substance, obtained by the distillation of indigo, to which 

 the name aniline had been given (from the Portuguese " anil " 

 for indigo), and showed that this body could also be obtained 

 from benzene. 



Such then was the condition of chemistry shortly before 

 1856 ; no one, least of all Perkin or Hofmann, had any idea 

 of the enormous potentialities lying dormant in the black, 

 viscid, evil-smelling tar they were patiently examining, but 

 were content to investigate the substance in a scientific manner 

 in the endeavour to find its composition and to see what fresh 

 facts it could be made to yield up. 



The First Period : 1 856-1 867. Mauve, Magenta, etc. 



At that time, in spite of much hard work at the College, 

 Perkin was so enthusiastic in his chemical studies that he 

 arranged a small laboratory in his home in the east of London, 



