420 



SCIENCE PROGRESS 



the almost complete replacement of the ordinary colours for 

 most purposes. 



The last decade has also seen the development of yet 

 another class of dyes, the so-called " sulphur colours " produced 

 by treating almost any organic substance with sulphur and 

 sodium sulphide. 



For the most part they are amorphous substances of inde- 

 terminate chemical character made by purely empirical methods, 

 reminding one very much of the early days of dye chemistry. 



The colours so produced are of all shades, but are somewhat 

 drab and flat in tone and are used chiefly for dyeing the cheaper 

 classes of goods, such as shoddy. 



Such then is the position of the coal-tar colour industry at 

 the present day. 



Owing to the adoption of scientific methods, the encourage- 

 ment of research, and the fact that the great German firms are 

 in charge of chemists, as they should be, and not under the 

 thumbs of business men, however able the latter may be, we 

 find that Germany has established practically a world monopoly 

 of dye-stuffs. 



At the outbreak of war German firms provided about six- 

 sevenths of the world's consumption of synthetic dye-stuffs, 

 valued at £12,000,000 to £15,000,000, of which Great Britain 

 imported £1,800,000 in 191 2, her own production being only 

 to the value of about £200,000. 



Recent figures are not available, but for 1904 the proportion 

 of the exports of German synthetic dyes going to various 

 countries was officially given as : 



I 



