RESEARCH AND THE COAL-TAR DYE INDUSTRY 417 



These facts show once again the intensive cultivation of this 

 field of industry by the Germans, and the overwhelming impor- 

 tance of continuous and painstaking research. 



The successful production of cheap phthalic anhydride 

 from naphthalene thus forged the one missing link in the 

 chain of processes necessary for the commercial synthesis x)f 

 indigo from coal-tar, and from that date— 1896 — the problem 

 may be said to have been solved. As far as the Hoechst works 

 are concerned, however, matters must have seemed somewhat 

 serious, as they had invested enormous sums of money in 

 research in indigo and had obtained practically no return, 

 and now had the chagrin of seeing the entire industry passing 

 apparently into the hands of their competitor and erstwhile 

 partner. 



In 1900, however, Pfleger, of the Deutsche Gold und Silber 

 Scheide Anstalt in Frankfurt, found that if phenjd-glycine 

 (obtained from aniline) were fused with sodamide instead of 

 with caustic potash, a nearly quantitative yield of indigo 

 was produced, so that after acquiring the patent the Hoechst 

 works were now in a position to challenge the Badische 

 Company for the world's indigo trade, resulting in a big drop 

 in prices ; but the two firms soon came to an agreement on the 

 matter, and from that day forward the two great chemical 

 factories have absolutely controlled the world's markets and 

 incidentally have almost ruined the Indian indigo industry, as 

 may be seen from these figures : 



Value of Exports of Indigo from British East India 



Year. Value in £. 



1896 . . 3,569,670 



1897 



1902 

 I905 

 I908 

 191 1 

 I913-I4 



1,980,319 



1,234,319 



556,405 



424,849 



225,000 



65,000 



whilst, of course, the acreage under cultivation has sunk pari 

 passu : 



Year. Acres. 



1894-5 552,000 



I900-I 300,000 



1904 223,000 



1905 171,000 



