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PROFESSORS AND PRACTICAL MEN 37 
The discovery of the atmospheric burner was not an 
accident. It arose from the desire of Bunsen to have a gas- 
flame that would not smoke his flasks; and it was contrived 
by a stroke of genius. But what an accident for you that 
a man of genius should want a smokeless flame! When I 
was a student in Bunsen’s laboratory, there came to it Carl 
Auer von Welsbach, in the spirit of an unalloyed philosopher, 
eager to solve some problems about the group of chemical 
elements that seemed, of*all, the most remote from any daily 
“human needs. He noticed the remarkable glow of the mixed 
oxides when a flame impinged upon them. And so he begat 
the gas-mantle. Again I say, no accident for him, but again 
what an accident for you, that a man of genius should want to 
investigate the mystery of rare earths ! 
I need not ask you where the gas industry would be to-day 
without these windfalls from the tree of scientific knowledge, 
whose branches, be it remembered, wave most vigorously in 
the upper air. Instead of in this assembly of comfortable 
gentlemen, enduring so kindly the garrulity of a professor, 
you might perchance have been found in Trafalgar Square, 
listening under the banner of the unemployed to more moving 
eloquence. 
By what definite planning are you to get discoveries of this 
kind made? The answer is, I think, by treasuring your men 
of genius, and letting them work in the light of their genius. 
Surely the time has gone by to wonder whether true scientific 
work, carried on in the spirit of a philosopher, by a man of 
genius with his feet upon the earth, subserves the material 
needs of humanity. Who is there that will dare to set his 
. finger on any patch of new natural knowledge and say: ‘ This 
may be edifying, but it is nothing to us’? 
__ When, therefore, you seek to bring science into your service, 
beware of unduly fettering the minds and discriminating the 
topics. This seems to be the hardest lesson of all for the 
