176 Intelligence and Miscellaneous Articles. 



blendes ; I hope it will not be long ere I possess more ample infor- 

 mation on this point. 



The gallium which I extracted from the blendes came really from 

 those minerals, and not from the metallic zinc (Vieille-Montagne) 

 employed for the precipitations ; for I have obtained no traces of 

 gallium with quantities of this zinc greater than what would have been 

 necessary of blende to get a very pure spectral reaction of gallium. 



My last investigations have confirmed the scarcity of gallium in 

 blende. The extreme delicacy of the spectral reaction had even 

 caused me to estimate too high the quantities obtained. I do not 

 think I exaggerate in saying that, at the time of my first observa- 

 tion, I possessed at most T fo of a milligramme of the new substance 

 dissolved in a very little drop of liquid. I may remark that spectral 

 examination of so minute a quantity would have been impossible 

 before the considerable reduction which I made in the dimensions 

 of the apparatus for obtaining electrical spectra, and without the 

 employment (which I adopted) of very small sparks. 



If, as I suppose, there is no error concerning the nature of my 

 gallium-alum, the existence of this salt fixes the atomicity of the 

 new element, and assigns to its oxide the same chemical function as 

 that of alumina. The oxide of gallium will therefore be written 

 Ga 2 3 , — Comptes Rendus de VAcademie des Sciences, Dec. 6, 1875, 

 pp. 1100-1104. 



ON THE SPECTRUM OF GALLIUM. BY LECOQ DE BOISBAUDRAN. 



I have again measured the wave-lengths of the lines of gallium 

 under conditions of accuracy which the feeble brightness of the 

 spectrum obtained did not permit me to realize at the time of my 

 first determination* ; and I have found precisely the same number 

 for the principal line, while the less brilliant one is a little less re- 

 frangible than I at first estimated it. 



"With the chloride of gallium, considerably more concentrated f, 

 which I have recently submitted to the action of the electric spark, 

 I have observed no other lines than the two following ; if, then, 

 others should be found with highly concentrated solutions, they can 

 only be faint. 

 Position on 



micrometer. X. 



a 193-72 417-0 



fi 208-90J 403-1 



' Narrow, strong. Notably brighter in a 

 spark of medium length than in a very 

 short spark. 

 Narrow, well marked, but much fainter 

 than a 193*72. Notably brighter with 

 a medium spark than with a very short 

 one. 



The line a 417*0 is characteristic of gallium • this is a very delicate 

 reaction. — Comptes Rendus deVAcad. des Sci. Jan. 10, 1876, p. 168. 



* Comptes Rendus, vol. lxxxvi. p. 494, Sept. 20, 1875 ; Phil. Mag. [IV.] 

 vol. 1. p. 415. 



t The relative intensities indicated in the description of the lines refer 

 to the mean state of concentration of the solution now employed. 



% The line Ga/3 is much more difficult to measure than Ga et • I never- 

 theless do not think that the error of X much exceeds 0*1. 



