DECOMPOSITION OF BORACIC ACltf. 19 



I made another experiment on the operation of potassium 

 on the olive coloured substance, and exposed the mixture to 

 a small quantity of ether, hoping that this might contain 

 only water enough to oxigenate the potassium; but the 

 same result occurred as in the last case ; and a combination 

 of potash and the olive coloured substance was produced, 

 insoluble in ether. 



I covered a small globule of potassium with four or five in vacuo, 

 times its weight of the olive coloured matter, in a platirta 

 tube exhausted, after being filled with hidrogen; and heated 

 the mixture to whiteness : no gas was evolved. When the 

 tube was cooled, naphtha was poured into it, and the result 

 examined under naphtha. Its colour was of a dense black* 

 It had a lustre scarcely inferior to that of plumbago. It 

 was a conductor of electricity. A portion of it thrown into 

 water occasioned a slight effervescence ; and the solid mat- 

 ter, separated, appeared dark olive, and the water became 

 slightly alkaline. Another portion examined, after being 

 exposed to air for a few minutes, had lost its conducting 

 power, was brown on the surface, and no longer produced 

 an effervescence in water. 



Some of the olive inflammable matter, with a little potas- and , in con *f ct 

 , i , . i • i • /.,■ vrith noil nl- 



sium, was heated to whiteness, covered with iron filings, a i ngs . 



dark metalline mass was formed, which conducted electri- 

 city, and which produced a very slight effervescence in wa- 

 ter, and gave by solution in nitric aeid, oxide of iron and 

 boracic acid. 



The substance which enters into alloy with potassium, and Trlie basis °* 

 with iron, I am inclined to consider as the true basis of the 

 boracic acid. 



In the olive coloured matter this basis seems to exist in Olire coloured 

 union with a little oxigen ; and when the olive coloured malter " 

 substance is dried at common temperatures, it likewise con- 

 tains water. 



In the black nonconducting matter, produced in the com- Black matter. 

 bustion of the olive coloured substance, the basis is evi- 

 dently combined with much more oxigen ; and in its full 

 state of oxigenation it constitutes boracic acid. 



From the colour of the oxides, and their solubility in alka- The boracic 

 lis, from their general powers of combination, and from the fal^™^ 1 * 

 C 2 conducting 



