82 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistky and Physics. 



1. An Attempt to Produce a Compound of Argon. — Assum- 

 ing that any compound which argon might form would be 

 endothermic, and would hence require a large amount of energy 

 and a high temperature for its production, and assuming also that 

 such a compound would need to be quickly cooled in order to 

 prevent its decomposition, Fischer and Iliovici have passed elec- 

 tric sparks, as well as the electric arc, between poles of cadmium 

 in liquid argon. Cadmium was selected for these preliminary 

 experiments on account of the fact that Kohlschtitter and M tiller 

 had found that the pulverization of cadmium by the electric 

 discharge was abnormally great in argon gas, as compared with 

 other gases. The argon was prepared from atmospheric air by 

 the absorption of the other gases by means of calcium carbide. 

 An elaborate apparatus was devised for carrying out the experi- 

 ments, in which it was found necessary to keep the argon at a 

 pressure near that of the atmosphere, for liquid argon boils at 

 — 189*6° C. under a pressure of 760 mm , while it solidifies only 

 2*70 below this point, and below a pressure of 500 mm liquid 

 argon does not exist. As a result of the passage of electric 

 sparks and the arc through this liquid there was produced a new 

 compound, cadmium nitride, due to traces of nitrogen in the 

 argon used. This nitride, which was mixed with pulverulent 

 metallic cadmium in the product produced by the arc, gave off 

 nitrogen when heated in a vacuum, and this nitrogen was found 

 to contain a considerable amount of argon. The authors con- 

 sider this argon as due to adsorption, but propose to continue 

 their experiments under different conditions. — Berichte, xli, 3802. 



h. l. w. 



2. Hhiplosive Crystallization. — Haying occasion to evaporate 

 a solution containing a sulphate and a thiosulphate enclosed in a 

 bell-jar under a diminished pressure of about 20 mm , Weston 

 found that an apparent explosion violent enough to break the bell- 

 jar had occurred during the night, when the liquid had become 

 very concentrated. Soon afterwards he attempted to crystallize 

 two solutions of a sulphite, which were probably supersaturated, 

 under the same conditions. In this case he saw a part of the 

 contents of one of the dishes violently ejected so that the dish 

 was broken, the other dish was upset, and the whole apparatus 

 was so shaken that the glass plate upon which the bell-jar rested 

 was broken. The author is of the opinion that crystallization 

 was suddenly induced on the surface of the basin with a con- 

 sequent sudden increase in the vapor-pressure of the surrounding 

 liquid, which under the very low pressure existing in the bell-jar 



