on the Absorption-Spectra of Metals. 235 



devised by Sainte-Claire Deville and Debray*, renders it possible 

 to attain high temperatures with great facility, and Stas has already 

 employed their method in the distillation of silvert. The lime still 

 arranged by him has been modified in that about to be described, 

 in order that the metallic vapour might be conducted into a lime 

 tube or tunnel heated to whiteness, so placed that a beam from an 

 electric lamp couid readily traverse it. 



Description of the Apparatus and method of Manipulation. 



The apparatus employed is shown in the figure, in which A 

 is the block of lime % divided horizontally by a plane through the 

 axis of the tube (B B'), this tube being 16 centims. long and 30 

 millims. diameter. The receptacle (C) communicates with the 

 centre of B B' and is open at the upper surface of the lime block, 

 in order to admit of the introduction of the oxyhydrogen blowpipe 

 (D), which is provided with a thick nozzle of platinum 20 millims. 

 in diameter. The ends of the tunnel in the lime were closed by 

 glass plates held on by a suitable clip. Small lateral orifices were 

 cut in the lime for the insertion of tobacco-pipe stems, through 

 which a stream of hydrogen could be passed into the tube and 

 receptacle. 



An electric lamp (F), in connexion with a 30-cell Bunsen's 



* Ann. de Chimie et de Physique, torn. lvi. p. 413. 



t Stas, ' Sur les lois des proportions Chimiques,' p. 56. 



J We are indebted to the well-known metallurgist, Mr. J. S. Sellon, of the 

 firm of Johnson and Matthey, for a pure variety of limestone from which the 

 blocks were prepared, and it answered its purpose admirably. 



