34tt • Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. Barium Sub-oxide and the Preparation of Metallic Barium. 

 — According to Winkler, magnesium reduces the alkaline earth 

 oxides, but he was unable to isolate the metals from the resulting 

 mixtures. Guntz has now repeated Winkler's experiment with 

 barium oxide and magnesium in a vacuum at a high temperature 

 with the expectation of collecting the metallic barium by distilla- 

 tion. It was found, however, that when the calculated quantities 

 of the substances were thus treated at about 1100°, approximately 

 one-half of the magnesium distilled off together with traces of 

 barium. Upon examination of the residue it appeared that a sub- 

 oxide of barium, Ba 2 0, had been produced. This forms a black 

 fritted mass, the properties of which are similar to those of metal- 

 lic barium, since it decomposes water, gives Ba s N 2 with nitrogen 

 at a red heat and at the same temperature yields BaH 2 . 



When aluminium, a non-volatile metal, was used in place of 

 magnesium in the experiment mentioned above, it was found that 

 crystallized barium of 98 '8 per cent purity was obtained at once 

 at near 1200°, and by a second distillation in a vacuum it was 

 obtained absolutely pure. This new method applies equally well 

 to strontium and furnishes an easy means of obtaining these 

 metals, which, up to the present time, have been so difficult to 

 prepare. — Comptes JZendus, cxliii, 339. h. l. w. 



2. The Thermal Formation of Nitric Oxide and Ozone in 

 Moving Gases. — Franz Fischer and Hans Marx have made the 

 interesting observation that ozone, as well as hydrogen peroxide 

 and nitric oxide, may be obtained by burning hydrogen in air or 

 oxygen by the use of a rapid current of the oxidizing gas, as a 

 jet blown through the hydrogen flame. It has been previously 

 known that suddenly cooling the hydrogen flame in other ways 

 gives nitric oxide and hydrogen peroxide, but the formation of 

 ozone from this source is new. They have found also the previ- 

 ously unknown fact that a rapid current of air blown over the 

 glowing Nernst pencil gives ozone in addition to nitric oxide, and 

 it appears that the proportion of ozone increases, in its relation to 

 the nitric oxide, as the rapidity of the current of air increases. 

 Quantitative results have not yet been obtained, but it seems possi- 

 ble to produce in this way enough ozone so that the nitrogen per- 

 oxide produced at the same time, when led into water or sulphuric 

 acid, will yield no nitrous acid, but nitric acid exclusively. — 

 Berichte, xlix, 2557. h. l. w. 



3. The Action upon Carbon of Oxygen, Carbon Dioxide and 

 Steam. — It has been found by P. Farup that, under the same con- 

 ditions of experiment, water vapor and carbon dioxide act upon 

 solid carbon at 850° C. with the same speed, while oxygen acts at 

 this speed at about 450°. According to the temperature-coefficient 



