Chemistry and Physics. 509 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and "Physics. 



1. Utilization of Atmospheric Nitrogen. — In a paper read 

 before the Faraday Society, Dr. Albert Frank has given an 

 interesting account of recent progress in the preparation of nitro- 

 gen compounds from the nitrogen of the air, particularly in the 

 form of calcium cyanamide, to which the commercial name nitro- 

 lim has been given. He discusses the production of Chili salt- 

 peter and the approaching exhaustion of this source of nitrogen 

 supply, and gives interesting data in regard to the production of 

 ammonium sulphate in the gas industry. He indicates the 

 increasing demand for nitrogenous compounds for agricultural 

 fertilization, and shows that the synthetic products are assuming 

 great importance. He states that the production of nitrates by 

 the oxidation of atmospheric nitrogen is making excellent pro- 

 gress in Norway, but it is his opinion that the Norwegian salt- 

 peter will remain the only direct competitor of the Chilian variety, 

 on account of the cheapness with which electrical energy can be 

 obtained in that country, which has unrivalled resources of water 

 power. He states that calcium cyanamide has been found to be 

 a satisfactory nitrogenous fertilizer, and gives an account of its 

 preparation. The atmospheric nitrogen is first concentrated by 

 the fractional distillation of liquid air by the Linde method. 

 The remaining oxygen is then removed by passing the gas over 

 heated metallic copper. The nitrogen is then absorbed by finely 

 ground calcium carbide in a heated retort, according to the equa- 

 tion CaC a >+N 9 =CaCN 2 + C. The product contains'from 57 to 63 

 per cent of calcium cyanamide, giving about 20 to 22 per cent of 

 nitrogen. The product is used directly as a fertilizer, and ammonia 

 can be prepared from it very readily by the action of steam upon 

 it. Works for the manufacture of this product have been started 

 in many localities, most of which are in Europe, but one has been 

 started on the Canadian side at Niagara Falls, and another in 

 Japan. It is estimated that at the end of the present year works 

 for the production of 45,000 tons of nitrogen by the cyanamide 

 process will be in operation. — Chem. News, xcvii, 289 and 303. 



H. L. W. 



2. The Action of Radium Emanation on Solutions of Copper 

 Salts. — Last year the sensational announcement was made by 

 Ramsay and Cameron that they had observed the production of 

 alkali metals, particularly lithium, in solutions of copper salts 

 which had been subjected to the action of the radium emanation. 

 These results appeared to be of so much importance that Mdme. 

 Curie and Mdlle. Gleditsch have attempted to reproduce them. 

 In the first place they placed a solution of copper salt in a little 



