May 25, 1917] 



SCIENCE 



493 



does not readily combine with other ele- 

 ments, and that animals and plants, with 

 very few exceptions, can not use free nitro- 

 gen as food. But the free form is plentiful, 

 since it makes up about four fifths of the 

 atmosphere, while the greater portion of 

 the remainder is oxygen. The specific prob- 

 lem, then, is to cause those two gases to 

 unite, or to find some other way of "fix- 

 ing" the nitrogen. This has been accom- 

 plished, and while the history of the com- 

 mercial process now in use is full of interest, 

 it must be passed here with mere mention. 

 It should be noted in passing that Caven- 

 dish, an English chemist, showed as early 

 as 1785 that nitrogen and oxygen could be 

 made to unite under the infiuence of the 

 electric spark, and that the product wovdd 

 react with water to give nitric acid. At 

 that day, however, electricity was regarded 

 as a mere toy, and no one dreamed of the 

 possibilities locked up in that interesting 

 though, to the average person, seemingly 

 useless, laboratory experiment. 



In 1898, Sir Wm. Crookes aroused inter- 

 est in this problem again by calling atten- 

 tion to the future exhaustion of the Chile 

 saltpeter beds, and urged a study of meth- 

 ods for fixation of nitrogen. In 1902, Brad- 

 ley and Lovejoy, two American chemists, 

 published an account of the commercial ap- 

 plication of the Cavendish experiment men- 

 tioned above, while to-day the manufacture 

 of nitric acid by that process in Norway is 

 a business in which more than $30,000,000 

 is invested. Immense sums have been spent 

 in its development in Germany and else- 

 where. 



At present, the manufacture of calcium 

 carbide, so largely used in the production 

 of acetylene for lighting and heating pur- 

 poses, offers an important method for fix- 

 ing nitrogen. The manufacture of the car- 

 bide was begun in this country several 

 years ago and is now one of the leading in- 

 dustries of Niagara Falls. Frank and 



Caro, German chemists, found that the car- 

 bide could be made to combine with nitro- 

 gen in such a way as to produce a valuable 

 fertilizer. The nitrogen it contains can 

 readily be converted into ammonia, and 

 from the latter nitric acid can be prepared. 

 As a matter of fact the Germans are now 

 producing 600,000 tons of the carbide an- 

 nually in order to supply, through the re- 

 actions indicated, the nitric acid required 

 to make explosives for the war. 



In this brief and superficial fashion, I 

 have tried to make it clear that the pre- 

 paredness which the nations demand is two- 

 fold — agricultural as well as military — and 

 that, in essence, both are largely chemical. 

 Cheap fertilizer must be furnished in times 

 of peace, and nitric acid and other materials 

 for explosives in times of war. So much 

 for the formulation of the demand. The 

 real problem is to furnish the means by 

 which this program can be successfully 

 carried through. 



So far as the chemical part of the pro- 

 gram is concerned, two specific require- 

 ments must be met. First, there must be 

 adequate training in the fundamentals of 

 chemistry, and second, there must be op- 

 portunity for chemical research. The first 

 is conceded by everybody, but many highly 

 intelligent educated people do not under- 

 stand research, and therefore call it theo- 

 retical and impractical. The cry is for ap- 

 plied science, for something practical. 

 They fail to recognize the fact that there 

 can be no applied science until there is 

 science to apply. It is not strange that 

 Huxley, with his extraordinary precision 

 of thought and remarkable command of 

 language, long ago pointed out that what 

 people call applied science is nothing more 

 than the application of the methods of pure 

 science to particular classes of problems. 

 Some one must patiently and laboriously 

 determine the facts and formulate the prin- 

 ciples before there can be any commercial 



