Chemistry and Physics. 387 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. A New Method for Producing Aniline and the Analogous 

 Bases. — It has been found by Sabatier and Senderens that free 

 hydrogen, acting at a slightly elevated temperature in the pres- 

 ence of certain finely-divided metals, is capable of attaching 

 itself to the molecules of a number of unsaturated organic com- 

 pounds, and that this method of hydrogenation is capable of 

 very readily transforming nitro-benzol and analogous nitro-com- 

 pounds into aniline and the corresponding bases. Copper (pre- 

 pared by the reduction of its oxide) at a temperature of about 

 300° to 400° acts rapidly upon a mixture of nitro-benzol and 

 hydrogen, the latter being in excess. The reaction is prac- 

 tically complete, the aniline is almost colorless, and the metal is 

 not altered by continued use. Nickel acts even more readily 

 than copper, and it may be used for this reaction at about 200° ; 

 but it is liable to cause an excessive fixation of hydrogen, for at 

 250° some ammonia and benzol are formed, while at 300°, with a 

 large excess of hydrogen, methane and ammonia are the chief 

 products. Platinum-blacksponge, and platinized asbestos effect 

 the reduction of nitro-benzol and similar bodies at a temperature 

 of about 230°-210°. Water-gas or purified illuminating-gas may 

 be substituted for hydrogen in these reductions ; in fact, in the 

 case where copper is used, carbon monoxide takes part in the 

 reaction, being oxidized to carbon dioxide to a considerable 

 extent. In view of the cheapness of water-gas, it is expected 

 that this method will find practical application in the manufac- 

 ture of aniline, in place of the customary reduction in the wet 

 way by means of a metal and an acid. — Comptes Rendus, cxxxiii, 

 321. h. l. w. 



2. On the Existence of Ammonium. — An unsuccessful attempt 

 to isolate ammonium has been made by Otto Ruff. In the first 

 place, potassium iodide was dissolved in liquified ammonia in a 

 cell which branched into two compartments at the bottom, and 

 an electric current was passed through the liquid by means of 

 platinum wires which passed through the bottoms of the two 

 branches, the cell being kept at a temperature of — 10°. Under 

 these conditions very small drops of a liquid having a metallic 

 appearance with the color of copper were formed at the negative 

 pole, and these dissolved in the ammonia, giving the intense blue 

 color which potassium-ammonium, KNH 3 , is known to give. 

 Similar experiments were then conducted with ammonium iodide 

 in place of the potassium iodide, but in this case hydrogen was 

 continually given off, and no blue color, nor any other evidence 

 of the formation of ammonium, was observed. The last experi- 

 ment was repeated with a closed cell so that the evolved hydro- 



