Intelligence and Miscellaneous Articles. 239 



The saline solutions are pulverized by a jet of compressed air ; 

 the air, charged with powder, enters a regulator, into which the 

 gas also comes, and whence a mixture issues of constant composi- 

 tion. This mixture passes into a vertical tube of 19 millims. 

 diameter, capped with iron-wire gauze, above which it burns with 

 a conical flame 6-8 centims. in height. The height of the inner 

 cone varies from 3 or 4 centims. to zero ; and the flame can be 

 rendered oxidizing or reducing. 



By means of a lens the image of the flame is thrown upon the 

 slit of the spectroscope. Two spectra are then seen, the one above 

 the other. The lower spectrum is produced by the light of the 

 blue surface ; and all the lines of which it is composed remain at 

 exactly the same height. The other is produced by the flame 

 proper ; and the lines belonging to it encroach upon the lower 

 spectrum, by reason of the shape of the flame. 



When the apparatus is employed void of powder, the lower 

 spectrum shows brightly the carbon-lines. If we pulverize a solu- 

 tion of chloride of lithium, the following is observed : — The upper 

 spectrum shows a very bright red line and a feeble line in the 

 orange. The first of these appears of equal brightness throughout ; 

 the other becomes much brighter just at the point where it pene- 

 trates into the lower spectrum. Moreover the lower spectrum 

 shows distinctly a blue line (y of the electrical spectrum), which 

 terminates at the same height as the carbon-lines and is absent 

 from the upper spectrum. 



These characters will be again found with other metals : — 

 Sulphate of Thallium. — This gives its characteristic green line, 

 which is clearly strengthened on penetrating into the lower 

 spectrum. 



Chloride of Calcium. — The upper spectrum is deprived of the 

 line proper to the undecomposed chloride. The blue line is a little 

 strengthened on entering the second spectrum. 



Chloride of Strontium. — The upper spectrum offers nothing pe- 

 culiar ; the lower shows three faint blue lines, which belong to the 

 electric spectrum of strontium. 



Chloride of Barium. — The lines and bands of the upper spectrum 

 are reinforced on penetrating into the other, especially the bright 

 green line. 



Chloride of Magnesium. — The upper spectrum shows traces of 

 the lines a and y of the electric spectrum ; the latter is more visible 

 when the flame is oxidizing. The spectrum gives the line a very 

 bright, and close by the green line of carbon. This line is triple in 

 the electric spectrum ; I have only been able to distinguish two of 

 the components, the third being doubtless confused with the carbon 

 line. Of these two components the brightest is as bright as the 

 latter ; and as it is very near it, one can verify that they have the 

 same height. The line y is not reinforced in the lower spectrum. 

 Chloride of Iron. — The flame is pretty luminous, greenish yellow. 

 The upper spectrum consists of bands and numerous fine lines upon 

 a continuous ground ; the lower one shows three groups of suffi- 

 ciently visible lines, corresponding to the groups /3 and £ of the 

 electric spectrum between the green and the blue, and y in the 

 violet. 



