1906] Manufacture of Nitrate of Lime. 599 



Deutscher Cyanid Aktiengesellschaft* and others. Should the 

 company prove successful, it seems that an industry of con- 

 siderable importance will thereby be created in Norway. 



The following is a brief description of the Birkeland-Eyde 

 method, which is now in use in Norway for the manufacture of 

 nitrate of lime from air by a hydro-electric process. 



One of the main features in the process is a new kind of 

 electric furnace in which is produced a special flame which 

 Professor Birkeland claims to have discovered while engaged in 

 the solution of another problem. Together with Mr. Eyde he 

 has applied the flame to obtain a chemical combination of 

 oxygen and nitrogen. In Professor Birkeland's experiment, 

 the electrodes were placed equatorially between the poles of a 

 powerful electro-magnet, with a fixed distance between the points 

 of the electrodes of from one to two millimetres. A steady 

 flame was created, causing a loud noise, and running through 

 four octaves according to the strength of the electro-magnet. 



Amongst the chemical reactions which can be caused by the 

 flame is the oxydisation of the nitrogen of the air. 



Without going into the details of the construction of the 

 furnaces, it may be stated that it is claimed that the flame 

 is comparatively steady, and up to 1,000 horse-power can 

 safely be carried on two 1*5 centimetre water-cooled tubes of 

 copper which form the electrodes, thus producing a flame r8 

 metres in diameter ; and, further, that these flames can burn 

 continually without causing damage in a flat-shaped furnace 

 about eight centimetres wide and two metres long. Experi- 

 ments in manufacture have passed through various stages, 

 ending with an experimental station near Arendal, with 500 to 

 i,ood horse-power, and absorption towers of granite, each 

 measuring forty cubic metres. 



On the 2nd May, 1905, the first nitrate factory was opened at 

 Notodden. The factory contains three furnaces, each of 700 

 horse-power. These furnaces are stated to show great stability 

 and regularity, and treat some 75,000 litres of air per minute, 

 through which the flame is passed, producing a dark brown 

 substance named peroxyde of nitrogen. The gases are absorbed 

 and transformed into nitric acid in two rows of stone towers, 



* See article on ''Lime Nitrogen," Journal, May, 1905, p. 101. 



