418 Scientific Intelligence. 



water the latter gave with chromic acid the characteristic blue 

 color due to hydrogen peroxide. Moreover, they have proved 

 further that the slow combustion of ether in presence of water 

 produces hydrogen peroxide. A convenient apparatus for the 

 purpose consists of a large flask, containing enough ether to 

 cover the bottom, mixed with an equal quantity of water, and con- 

 nected with a wash bottle containing cold water. Through the 

 cork of the flask a wide tube passes, open at both ends, and also a 

 spiral of stout platinum wire and a tube bent at right angles 

 which joins it to the wasli bottle. By an aspirator connected 

 with this bottle, air is drawn into the flask by the wide tube. 

 Upon heating the spiral to redness and plunging it into the flask, 

 the current of air may be so regulated as to maintain the spiral 

 at a low red heat. Hydrogen peroxide is continuously formed, 

 the flask being from time to time shaken, the ether forming a 

 peroxidized product which is decomposed by the water producing 

 hydrogen peroxide which is dissolved in this water. — J. Chem. 

 Soc, lvii, 574, June, 1890. G. r. b. 



4. On the action of Carbon monoxide upon Metallic Nickel. — 

 Mond, Langer and F. Quincke have observed that when carbon 

 monoxide is passed over finely divided metallic nickel between 

 350° and 450° carbon dioxide is evolved and a black powder con- 

 taining a varying proportion of carbon and nickel is formed ; a 

 small quantity of metal being able to decompose a large quantity 

 of carbon monoxide. A sample containing 85 per cent carbon 

 and 15 per cent nickel, when treated with sulphuric acid, gave 

 up about two-thirds of its metal ; the remaining carbon being 

 readily attacked by steam, even at 350°, yielding hydrogen 

 and carbon dioxide only. On allowing the nickel to cool while 

 the carbon monoxide was passing over it, it was noticed that the 

 flame of a Bunsen burner into which the excess of gas was con- 

 ducted, became highly luminous ; and on heating the tube 

 between the metal and the outlet a brilliant mirror of metallic 

 nickel Avas deposited, mixed with a minute quantity of carbon. 

 Further investigation showed that when finely divided nickel, 

 obtained by reducing the oxide at 400° by hydrogen, is allowed 

 to cool in a slow stream of the monoxide, the gas is very readily 

 absorbed as soon as the temperature has fallen to 100°, and a gas 

 is obtained which the authors call nickel-carbon-oxide, in amount 

 about 30 per cent of the escaping gases. This gas at 180° is 

 decomposed into metallic nickel and carbon monoxide again ; 

 four volumes of the monoxide being obtained from one of the new 

 gas. Hence it has the composition Ni(CO) 4 . The gas is not 

 acted on by alkalies or acids. It reduces ammoniacal solutions 

 of cuprous chloride and silver chloride. Chlorine decomposes it 

 with formation of nickel chloride and carbonyl chloride. When 

 cooled in a freezing mixture, the gas condenses to a colorless 

 highly refractive mobile liquid, boiling at 43°, having a specific 

 gravity of 1-3185 at 17° and solidifying at —25° in needle shaped 

 crystals. Since neither cobalt, iron, copper or platinum forms a 

 similar compound, nickel may be readily purified in this way. 



