Septembeb 17, 1909] 



SCIENCE 



379 



escaping oil and gas, it was estimated that 1,500,- 

 000 barrels of water were discharged per day, and 

 with the liquid about 2,000,000 tons of solid 

 matter, so that ultimately a crater of 117,600 

 square meters was formed. The fire was eventu- 

 ally extinguished by pumping sand into the crater 

 with centrifugal pumps. 



Words of warning were given in regard to the 

 fear expressed by some as to overproduction of 

 oil; also he wished to dispel any illusions as to 

 the displacement of coal by oil, for the latter 

 constituted but a very small percentage of the 

 fuel used, or that would become available; al- 

 though no one could say how much petroleum was 

 yet to become available, there was not much like- 

 lihood that it could ever revolutionize the fuel 

 industry. 



In connection with this address it might be 

 mentioned that series of papers were presented be- 

 fore the metallurgy, organic and law sections upon 

 fuel and methods for determining its value, coal- 

 du?t explosions, gas-producers, sources of oils, as 

 shale oil, uses of by-products, and the smoke 

 problem. The International Congress on Pe- 

 troleum met for two days previous to the congress. 



The special lecture which attracted most atten- 

 tion was undoubtedly that of Professor A. 

 Bernthsen on " The Utilization of Atmospheric 

 Xitrogen, Particularly for the Manufacture of 

 Air-saltpeter," given in Professor Armstrong's 

 lecture theater. Having directed attention to the 

 importance of soluble nitrogen compounds for 

 fertilizing purposes, tracing the history of our 

 knowledge of the value of nitrogen in plant and 

 animal life, the lecturer said that of the 2,000,000 

 tons of Chili saltpeter exported annually Germany 

 took one third. Crookes prophesied that the sup- 

 ply of saltpeter would be exhausted before many 

 years had passed, and by 1935 there would be 

 such a demand for wheat that, even if all the 

 ground now available were planted, the yield per 

 acre must be increased from 12.7 to 20 bushels in 

 order to supply it. Twelve million tons of salt- 

 peter would be required per annum in addition to 

 the 1.750,000 now being used. Even if Chili still 

 had 50,000,000 tons of saltpeter in 1935, the four 

 following years would exhaust it. 



The nitrogen of the air amounts to about four 

 billion tons. On the basis of the present annual 

 consumption, allowing no replacement, the air 

 contains enough nitrogen to provide fourteen 

 thousand million years' supply of saltpeter. The 

 world's demand increases by about 100,000 tons 



per annum. Shortly by the process described, and 

 demonstrated on a large scale by the lecturer, 

 that amount would be placed upon the market 

 every year. 



The comparative value of ammonium, nitrate 

 and nitrite compounds was dealt with in some 

 detail and reference made to the sources of these 

 classes of compounds. 



The different methods employed in the fixation 

 of atmospheric nitrogen may be divided into three 

 groups. First, direct formation of ammonia from 

 its elements, both of which have to be isolated 

 for the purpose. Second, the formation of metallic 

 nitrides and cyanogen compounds, which are sub- 

 sequently decomposed into ammonia compounds. 

 And third, those methods which aim at the direct 

 oxidation of atmospheric nitrogen to nitrites or 

 nitrates. These methods were discussed from sci- 

 entific, practical and economic points of view, 

 attention being given especially to the cyanides, 

 nitrolime, " Stickstoflalk." 



In the combustion of nitrogen in oxygen, there 

 is an equilibrium for each temperature between 

 the nitric oxide produced and the nitrogen and 

 oxygen, hence the amount of nitric oxide produced 

 at any temperature can not exceed that corre- 

 sponding to the state of equilibrium for the par- 

 ticular temperature. The following figures give 

 the percentage produced: at 2,200° C, the gases 

 contain 1 per cent, nitric oxide, at 2,571° C. 

 2 per cent., at 2,854° C, 3 per cent, and at 

 3,327° C. 5 per cent. Therefore the air must be 

 heated to as high a temperature as possible and 

 the products cooled as rapidly as possible to 

 reduce the decomposition of the nitric oxide to 

 free nitrogen and oxygen to a minimum. 



The numerous methods proposed for accom- 

 plishing this, especially that of Cavendish, who in 

 1785 said it could be accomplished by electric 

 spark discharges, were discussed. Particular at- 

 tention was given to the modern practical proc- 

 esses of Bradley and Lovejoy, Birkeland and Eyde. 

 The original papers, or this lecture, which may 

 be had in printed form from the Badische Anilin- 

 und Soda-Fabrik, should be consulted for the 

 details. The process of his company, as worked 

 out . by Schonherr and Engineer Hessberger in 

 1905, and claimed to be superior to those of 

 Birkeland and Eyde, was then described. This 

 dispenses with magnets used for creating a strong 

 field, which spreads out the flame into the shape 

 of a flat, more or less circular, disc. Schonherr 

 produces his arc inside an iron tube of compara- 



