SOILS FERTILIZERS. 747 



methods of producing electrical energy and of freeing the nitrogen of the air from its 

 associated constituent-. The mosl promising results with the Prank process from a 

 commercial standpoint have apparently been obtained in [taly, where 'heap and 

 abundant water power has been utilized in tin- generation of electrical energy. 



The most successful electrical method which has yel been suggested, judging by 

 the results reported, isthal of K. Birkeland and 8. Eyde, of < hristiania, Norway. 

 The inventors of this process, for which patents have been taken oul in this country 

 as well as in Europe, claim that it has uol been possible up to the time of their 

 discoveries to utilize electric energy in a single powerful arc for- the production of 

 nitric compounds from the atmosphere in an economical manner. 



A.s stated in the United state- patents, their invention is based upon the fact that 

 electrical discharges between electrodes placed within a magnetic field may be dis- 

 persed by the action of the magnets, and that "an electric arc of high or low 

 tension may be dilated or spread into a Large permanent flame having the shape of 

 a sheet or a disk of a volume several hundred times as large as a regular or primary 

 arc of the same energy when the electrodes are placed in a suitable manner in a pow- 

 erful magnetic field— for instance, between the poles of a magnet and transverse to 

 the flux of said field." 



Jn this way it is possible "to transform a great part of the electrical energy into 

 heat capable of being absorbed by certain gases, as chemical energy under conditions 

 which are attended by valuable chemical reactions. This is clue to the fact that the 

 efficiency of a flame in endothermic chemical processes is a function of the ratio 

 between the volume and the temperature of the flame. [It is claimed that by this 

 process it is possible] to have furnaces at continuous work with several hundred 

 kilowatts at each flame, the heat being economically utilized, a result which was w >\ 

 heretofore possible unless the energy employed for each arc was only very small." 



It is reported that in works which have been built at Notodden, Norway, to 

 utilize water power from large falls in that vacinity 1,500 kg. per day of water-free 

 nitric acid are now being made. The final product is in form of calcium nitrate, the 

 fertilizing value of which is being studied by a number of investigators (E. S. R., 

 17, p. 449). 



Nitric acid and nitrates from the nitrogen of the air {Ztschr. Angew. Chem., 

 19(1906), No. 1, /v. 37,38). — This article deals with the Birkeland and Eyde process 

 for the preparation of nitrogen compounds from the nitrogen of the air, and describes 

 particularly the progress that has been made in utilizing for this purpose the abun- 

 dant power furnished by waterfalls in southern Norway. 



It reports that the success of small experimental works has been such that a num- 

 ber of larger plants are now being established at various places. The general prin- 

 ciples upon which better methods of utilizing electric power have been based in this 

 process are stated in the preceding abstract. It is stated that in this method the 

 gases after treatment contain from 1 to 2 per cent of nitric oxid, which is absorbed 

 partly in water and partly in milk of lime. 



The solution thus obtained is concentrated and saturated with limestone and 

 finally obtained either as crystallized calcium nitrate or by addition of an excess of lime 

 according to Collett's prowess, in form of a basic fertilizer known commercially as 

 " basic lime niter." The latter contains from 8 to 9 per cent of nitric nitrogen and 

 about 22 per cent of lime as hydroxid and carbonate. This material has given very 

 good results as a fertilizer in the experiments which have been made with it. 



Calcium nitrate manufacture in Norway (Engin. and Min. Jour., 81 (190>'>), 

 No.4,p. 192). — A brief note on an experimental factory at Notodden, employing the 

 Birkeland and Eyde process, referred to above, which has been in operation since 

 the beginning of 1905, and on the construction of large additional works at .Sviilgfos, 

 near Skien, where 30,000 horsepower will be available. 



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