222 Discovery of Columbite in Chesterfield, Mass. 



heat of the blowpipe, when globules of metallic tin made 

 their appearance. 



5. To another portion of the muriatic solution, (2.) ren- 

 dered neutral by ammonia, was added oxalate of ammonia : 

 a slight cloudiness was perceptible, and after several days a 

 small precipitate collected at the bottom of the solution ; — 

 thus indicating the presence of lime. 



6. The remainder of the original muriatic solution, (2.) 

 was neutralized by the cautious use of ammonia, and to it 

 was added succinate of ammonia ; a copious precipitate of 

 oxide of iron made its appearance. 



7. The solution from which the iron had been thrown 

 down, (6.) was boiled with an excess of carbonate of soda, 

 which occasioned a precipitate of oxide of manganese. 



8. The white precipitate, insoluble in muriatic acid, (2.) 

 was thoroughly boiled with warm water. A portion of it 

 was digested in aqua ammonige; the liquid, after having been 

 passed through the filter, was saturated with muriatic acid, 

 without producing any cloudiness. Therefore it was infer- 

 red, that no tungsten exists in the mineral under examination. 



9. I then engaged in the following examination of the re- 

 mainder of the white precipitate, (2.) in which I took the great- 

 er interest, from never before having had it in my power to re- 

 peat any of the experiments that have been made upon the 

 compounds of columbium, on account of the rarity of that 

 metal; and I have thought it worth while to connect an ac- 

 count of them with the present notice, for the satisfaction of 

 those whose confidence, with regard to the nature of a doubt- 

 ful mineral, is increased by its chemical examination ; al- 

 though I am aware, it may appear superfluous to the mere 

 mineralogist, who is accustomed in such cases, to rely sole- 

 ly upon the characteristics of his science. 



A small portion of it, still moist, was placed upon a 

 piece of bibulous paper, which had been moistened with a so- 

 lution of nut galls ; the mass immediately assumed a rich or- 

 ange color. 



A portion of it was heated to redness in a platina crucible 

 along with six times its weight of carbonate of soda. The 

 resulting mass presented upon its surfaces delicate silky 

 white, prismatic crystals. Warm water was added until the 

 whole was dissolved. The solution when treated with the 

 following reagents, produced the following effects. 



