1915] on Science and Industrial Problems 329 



Bub one can almost hear the question, What was the good of 

 this \York ? If it ^vas desired to make sky bhie alizarine and the 

 reaction did not give the desired result, what was the object of further 

 investigation ? 



The reply is obvious, when the course of the chemical reaction 

 involved in the production of the indanthrene derivative is followed 

 a little more closely. The chemical fact, by virtue of which an 

 indanthrene derivative is formed, is the interaction of an amino 

 group in one substituted anthraquinone molecule and the bromine 

 atom in a second molecule, with consequent linking together of the 

 two molecules. 



Then comes the important question, Is this reaction a general 

 one ? Investigation soon proved that minute traces of copper influ- 

 ence in a surprising and general way the interaction of halogen 

 derivatives of anthraquinone with primary aromatic amines, and there 

 has resulted another new series of anthraquinone dye stuffs, of which 

 many, such as orange algol, bordeaux algol and indanthrene red, are 

 of great commercial importance. 



The following examples serve as types of the constitution of such 

 derivatives : — 



CO 



CO 



OCX) 



CO NH 



CO 



CO 



Ceo 



CO 



Now it may well be asked, what would have been the result of 

 the accidental occurrence connected with the installing of this new 

 apparatus for sky blue alizarine if skilled research assistance had not 

 been at hand ? Would it still have been called luck ? Will you try 

 to place yourselves in the position of the foreman in charge of the 

 operation and then reply to these questions ? 



Instead of receiving nothing but severe censure for carelessness, 

 that foreman, whoever he was,learnt to appreciate the value of the 

 skilled chemist in the works ; he would not be slow to let those 

 under him know his opinion on the subject, and so gradually 

 throughout the whole factory the leaven of scientific enquiry would 

 spread, even to the most recently admitted workman. 



