SCIENCE FOR LIFE 13 



immediate vicinity of the mines ; these and other 

 problems are being discussed by experts. We are 

 almost sure to discover new and better ways of harness- 

 ing winds and tides. Experts speak of the possibility 

 of unlocking the imprisoned sub-atomic energies of 

 which radio-active substances have given us so impres- 

 sive a glimpse, and hint that it is not an absurdity to 

 think of drawing from the supply of energy represented 

 by the stresses of the ether. In any case this is certain, 

 that in the domain of things Science is giving man an 

 increasing control of power. 



It is progress, we suppose, to make in considerable 

 quantity and economically what was previously pro- 

 curable in small quantity and wastefuUy. Thus the 

 Tyrian purple of the sea-snail is replaced by a similar 

 product of coal-tar. But far more important is getting 

 nitric acid and ammonia by tapping the free nitrogen 

 of the atmosphere. In 1892 Sir William Crookes 

 showed that a strong electric current passed through 

 air produced nitrous and nitric acids, and this was the 

 beginning of the fixation of nitrogen which has been 

 developed in many countries on a practical scale for 

 the production of explosives on the one hand and 

 fertilisers on the other. In Lord Rhondda's words, " If 

 we are to feed ourselves, we must begin by securing 

 a continual provision of the fixed nitrogen which is 

 necessary to feed our best food, and which we can 

 begin to make for ourselves, whenever we please." 

 (See 3rd edition [1918] of The Wheat Problem by Sir 

 William Crookes.) How life-saving has been the abstract 



