ARTIFICIAL PRODUCTION OF NITRATE OF LIME 363 



Prof. Birkeland by accident. Ordinary air is forced through 

 this disc of roaring flame, and emerges charged with nitrous 

 gases. This charged air is then quickly removed from the 

 vicinity of the flame, and is subjected to chemical treatment 

 in order to obtain the gases in the form of nitrite or nitrate 

 of lime. 



This process has been undergoing gradual industrial 

 development in Norway since June 1903, and, after being tried 

 upon scales of increasing magnitude, appears now to have 

 reached a position of considerable industrial promise and im- 

 portance. The first large installation of plant and machinery 

 commenced work at Notodden in May of last year, with three 

 furnaces of 700 h.-p. each, and the necessary absorbing towers 

 and other plant. After the operation of the Birkeland and Eyde 

 process at this factory had been witnessed by a number of indepen- 

 dent experts, and tests had been made of its working efficiency 

 during the summer months of 1905, a company was formed to 

 promote the further industrial development of the process. A 

 large number of German and Norwegian banks are lending their 

 support to this new undertaking, and a capital of 7,000,000 kr. 

 (£375 » 000 ) is being raised. The factory at Notodden has been 

 taken over by the new company, and extension of the works, 

 until it is in a position to utilise 30,000 h.-p., are contemplated. 



The annual output of calcium nitrate by this company, when 

 the works at Notodden have attained their full development, 

 is estimated at 20,000 tons. 



Ordinary nitrate of lime possesses the disadvantage, from 

 the agriculturist's point of view, that it is very hygroscopic, and 

 very readily soluble in water. This difficulty has been over- 

 come, it is stated, by preparing the basic nitrate in its place ; 

 and experiments have shown that this salt, as a manure, is equal, 

 if not superior, to natural nitrate of soda — the " Chili saltpetre " 

 of commerce. 



As regards cost, no very detailed estimates are yet available ; 

 but Dr. Otto Witt, who has himself investigated the process, 

 states that the equivalent of half a ton of nitric acid (100 per 

 cent.) can be produced per k.w. year, and that at Notodden, 

 where the water power can be very cheaply developed, this 

 amount of electricity costs only 16s. Since the value of the 

 lime required for operating the process is not great, when 

 compared with the value of the final product, it is expected that 



