400 Prof. W. N. Hartley and Mr. H. Ramage. 



Very strong band from 5598 to 5485. 



Band of continuous rays with other bands discernible in it. 

 Less refrangible edge of band 5445. 

 Band in the same at 5422, 5390, 5359, 5341, 5322. 

 The more refrangible edge of band 5304. 



Very narrow band in the blue, more like a very strong broad line 

 from 4222 to 4215. 



The magnesium oxide was identified by three bands, more or less 

 connected by diffused rays. 



1st. From 3929 to 3856 



2nd. 3834 3805 



3rd. 3805 3682 



On these bands were seen ten iron lines, six in the first principal 

 group and four in the second, all very faint, but with apparently the 

 following wave-lengths, which correspond wiih the lines seen in 

 oxyhydrogen flame spectrum of ferric oxide. They are also closely 

 in approximation to, and probably identical with, the following arc 

 lines, measured by Kayser and Runge in iron. 



3860-03 3856-49 3826-04 3824-58 



3758-36 3748-39 3745-67 3737-27 



3735-0 3722-69 3720-07 



Roasted Cleveland Iron Ore. Process for the Extraction of Gallium. 



This ore is a complex substance, and contains elements which 

 render the complete extraction of the gallium very difficult. It is in 

 great part soluble in strong hydrochloric acid, but the iron goes into 

 solutions as a ferric salt, and difficulties arise in attempting to reduce 

 it to the ferrous, state. Zinc and iron are both liable to contain 

 gallium, and, without a very careful examination of a quantity of 

 the metal, it would be wrong to use them as reducing agents, seeing 

 that the quantity of metal required in the process is large in com- 

 parison with the sample treated. Sulphurous acid and kindred sub- 

 stances yield sulphates which cause a quantity of the alkaline earths 

 to separate as sulphates, and, as these precipitate in faintly acid solu- 

 tions, there is a risk of basic gallium sulphate being carried down 

 with them. 



Dilute hydrochloric acid yields a solution poor in iron, but the dis- 

 solved matter is richer in gallium than the original ore. A large 

 proportion of silicic acid is, however, contained in the solution. 



Experiments were made on quantities of 50 grams of the ore, and 

 the spectra from the sesquioxide metals were carefully compared 

 with the spectra from the similar products from the metal, and we 

 find that, as in the comparison of the original samples of ore and 



