32-4 Professor Arthur W. Crossley [Feb. 5, 



is meant one who sets out to make new organic substances without 

 apparently any particular object in view, except that of filling the 

 pages of scientific journals with very long names and equally long 

 formulae, which have no particular interest for anyone. But our 

 organic chemist can afford to bear the brunt of this criticism with 

 equanimity ; for though the labours of any one chemist may not 

 seem to have furthered, to any appreciable extent, the aims of 

 scientific industry, yet, when the results of the labours of several such 

 research workers are put together and systematized or organized, 

 certain well-defined facts appear, of which scientific technical 

 chemists have not been slow to avail themselves. 



The aim of the research chemist in the particular instance 

 chosen was to j^roduce from anthraquinone (I), a substance obtained 



CO CO OH 



ceo OX)" 



CO CO 



(I) (11) 



by oxidizing the hydrocarbon anthracene contained in coal tar, the 

 greatest possible variety of colouring matters ; a perfectly definite 

 object, but how was it to be attained ? 



Synthetic chemistry had proved as long ago as 1869 that the 

 introduction of two hydroxyl groups into the anthraquinone molecule 

 gave rise to a brilliant red dye stuff, named alizarine (II), or perhaps 

 better known as Turkey red. For twenty years after this discovery 

 comparatively few related colouring matters were produced, these 

 few including flavopurpurine, anthrapurpurine, alizarine orange, 

 and alizarine blue. These colours cannot, however, be used to 

 dye cloth without the use of mordants, different shades being pro- 

 duced according to the mordant employed. Suddenly, about 

 twenty-five years ago, the anthraquinone dye industry began to 

 develop very rapidly, due largely to the discovery of derivatives 

 capable of being used without mordants and distinguished by a rare 

 solidity of colour of all shades of the spectrum — yellow, orange, red, 

 violet, blue, and green. In the last twenty years literally thousands 

 of these colours have been made, of which some have proved to be 

 useless from the commercial point of view, because they are not fast 

 to light or to the process of soaping, or because the brilliance of the 

 original shade was not permanent. Nevertheless, the manufacture 

 of a selection from among these thousands of colouring matters has 

 proved to be one of the greatest commercial enterprises of modern 

 times. (R. Schmidt, Bull. Soc, June 1914.) How has this result 



