404 CHEMICAL DISCOVERY AND INVENTION 



were made in connection with the isolation of argon from air by 

 removal of the nitrogen, and there can be no doubt that their 

 publication gave encouragement to the idea that it would be 

 possible to utilise the process for the production of nitric acid 

 and nitrates. In these experiments a mixture of oxygen and 

 atmospheric air supplied to an inverted glass globe of 50 litres 

 capacity containing a solution of caustic soda was exposed to a 

 kind of electric flame. Some difficulties were encountered in 

 producing a steady flame, but a definite relation was established 

 between the electric energy consumed and the amount of nitrate 

 produced. Passing over the work of the numerous experimenters 

 attracted to the subject in all the civilised countries of the 

 world, it may be noted as an interesting fact that the first 

 practical application of the principle of electric combination of 

 atmospheric gases to the production of nitrates was made by two 

 Englishmen, McDougall and Howies, in 1899. Their works were 

 not commercially successful, and another attempt was made by 

 Bradley and Love joy in 1902 in connection with the use of water 

 from Niagara, but it lasted only two years. 



The first practical success was achieved by Dr. Samuel Eyde, 

 Engineer of Christiania, in association with Professor Kristian 

 Birkeland, 1 who established the now famous works at Notodden 

 below lake Tinnsjo. The French Company which found the 

 greater part of the capital has also joined forces with the Badische 

 Anilin und Soda Fabrik which built works at Christiansand in 

 Norway, and two other German firms. The result has been the 

 establishment of two new Norwegian companies, of which one, 

 with a capital of 16 million krone (900,000), undertakes the 

 provision of water power from the Norwegian falls, and the other, 

 with a capital of 18 million krone (about 1,000,000), is con- 

 cerned in the application of this power to the manufacture of 

 lime saltpetre. 



There appears to be a little difference of opinion as to the 

 exact part played by the electric arc in causing the combination 

 of nitrogen and oxygen. Sir William Crookes and Lord Rayleigh 

 appear to hold the view that it is a question only of temperature. 

 Nitric oxide is an endothermic compound, and its production 

 according to the equation : 



N 2 -f 2 ~ > 2NO 



1 Professor of Physics in the University of Christiania, Norway. 



