84 Mr. Davy's Lecture on some new analytical Researches 
exhausted, after being filled with hydrcgene ; and heated the 
mixture to whiteness : no gas was evolved. When the tube 
was cooled, naphtha was poured into it, and the result exa- 
mined 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 matter sepa- 
rated, 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 efferves- 
cence in water. 
Some of the olive inflammable matter, with a little potas- 
sium, was heated to whiteness, covered with iron filings, a 
dark metalline mass was formed, which conducted electricity, 
and which produced a very slight effervescence in water, and 
gave by solution in nitric acid, oxide of iron and boracic 
acid. 
The substance which enters into alloy with potassium, and 
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 
union with a little oxygene ; and when the olive coloured 
substance is dried at common temperatures, it likewise con- 
tains water. 
In the black non-conducting matter, produced in the com- 
bustion of the olive coloured substance, the basis is evidently 
combined with much more oxygene, and in its full state of 
oxygenation, it consitutes boracic acid. 
From the colour of the oxides, their solubility in alkalies. 
