EDITORIAL. 829 



production than in concentration of the nitric acid. The latter has 

 not vet found a ] ><■]• !'»•< t technical solution, and so it has been found 

 most economical to market the product in form of calcium nitrate. 



For agricultural purposes especially the calcium nitrate is mixed 

 with an excess of lime, yielding a dry. easily handled material known 

 commercially a- "lime niter" (Kalksalpeter) , which contain- on an 

 average > s to 9 per cent of nitrogen and about 22 per cent of lime. A 

 number of experiment- have been made with tin- material which indi- 

 cate that it has a fertilizing value slightly superior to nitrate of soda 

 on soils benefited by Lime as well as nitrogen. 



In a recent article reviewing two important contributions to the 

 subject of fixation of atmospheric nitrogen, E. Etenouf enumerates 

 and discusses the relative efficiency of no less than four distinct 

 methods of accomplishing this result, viz. fixation by mean- of 

 micro-organisms, formation and decomposition of nitrids, the pro 

 duction of calcium cyanamid, and electrical oxidation: and expresses 

 the conviction that "by the time the Chili saltpeter beds are 

 exhausted chemists and engineers will be ready with practical and 

 economic methods of utilizing atmospheric nitrogen to meet the 

 demands of agriculture and industry." • 



The products of the various processes for fixing the nitrogen of 

 the air have not yet found their way into markets in sufficient quan- 

 tity to establish their commercial rating, hut Prof. Silvanus P. 

 Thompson, the eminent English physicist, in a recent Lecture before 

 the Royal Institution of London, asserts his belief that where condi- 

 tions are exceptionally good for the furnishing () f power at exceed- 

 ingly low rates, nitrogen compounds can he prepared by the Birke- 

 land and Eyde process at a price which will enable them to compete 

 with nitrate of soda in the market, becoming every year more valu- 

 able as the demand for nitrates increases and the natural supply 

 becomes exhausted. 



The development of these methods, while of great practical impor- 

 tance, is also of the highest significance as an illustration of the suc- 

 cessful application of the results of investigations in pure science to 

 practical affairs and commercial needs. The working out of these 

 methods on a practical basis is rendered possible only because of 

 the long -eric- of scientific investigations beginning with Cavendish 

 and continued by his successors in similar lines of work, which 

 were undertaken solely for the purpose of advancing chemistry and 

 physics as pure sciences and with no thought of practical results or 

 commercial rewards. 



