318 Intelligence and Miscellaneous Articles^ 



another the two mixed gases, at the same time that it rendered them 

 luminous. 



The presence of oxygen in a hydrogen-tube had probably some- 

 thing to do with its preparation. M. Pliicker has said that it was 

 possible to use steam for preparing these tubes, and that the passage 

 of the first electric discharges sufficed to place the hydrogen at 

 liberty : such a separation of mixed gases has appeared to M. Reit- 

 lin"-er to furnish the explanation of the stratification of the electric 

 lisht. He admits, for instance, that in a tube prepared with steam, the 

 hvdrogen and oxygen dispose themselves in alternate layers ; and 

 that the hydrogen, a much better conductor than the oxygen, is 

 less heated and becomes less luminous, that is, relatively obscure : 

 generally speaking, stratification would result from the disposition in 

 alternate layers of two gases unequally conductive. 



1st. A tube full of dry air under the pressure of 1*5 millim. gave 

 a spectrum in which only the rays characteristic of nitrogen were seen, 

 and which presented not the slightest trace of stratification : no very 

 sensible difference was perceivable between the two wide tubes and 

 the capillary tube of communication of which the entire apparatus was 

 formed ; the spectrum of the capillary part offered merely some rays 

 which were wanting in the spectrum of the wider parts. The intro- 

 duction of a small quantity of pure hydrogen caused the stratification 

 to appear in the wide tubes without sensibly modifying the aspect of 

 the corresponding spectra. In the narrow tube no appearance of 

 stratification was produced at first, but to the spectrum of nitrogen 

 there was superposed a bright spectrum characteristic of hydrogen. 

 The introduction of hydrogen being continued, and the pressure 

 raised to 6 millims., the light of the capillary tube became stratified 

 in its turn, and the tube presented somewhat the aspect of a chaplet 

 of brilliant pearls. 



2nd. The electric light was developed in the barometrical vacuum, 

 the mercury itself supplying the place of one of the electrodes : only 

 a white homogeneous light was perceived, without stratification. By 

 the introduction of some globules of air, there was immediately formed 

 a series of luminous layers alternately more or less brilliant, but 

 without the inequality degenerating into obscurity. A spectrum of 

 the light showed at the same time the rays of the mercury and 

 that of the" air. By regulating properly the intensity of the current 

 and the electric force of the introduced air, the layers less brilliant 

 can be brought to an almost complete obscurity. 



3rd. With simple gases no stratifications have been produced. — 

 Ann. cle Chim. et de Phys,, Jan. 1863, p. 114. 



ON THE SPECTRUM PRODUCED BY THE FLAME EVOLVED IN THE 

 MANUFACTURE OF CAST STEEL BY THE BESSEMER PROCESS. 

 BY PROFESSOR ROSCOE. 



The spectrum of this highly luminous and peculiar flame exhibits, 

 during a certain phase of its existence, a complicated but most 



