8 Mr. Davy’s Lecture on the Decomposition and Composition 
solution, the process stopped, the interior being defended 
from the action of the gas. 
With the substance from soda, the appearances and effects 
were analogous. 
When the substances were strongly heated, confined in 
given portions of oxygene, a rapid combustion with a bril- 
liant white flame was produced, and the metallic globules 
were found converted into a white and solid mass, which in 
the case of the substance from potash was found to be potash, 
and in the case of that from soda, soda. 
Oxygene gas was absorbed in this operation, and nothing 
emitted which affected the purity of the residual air. 
The alkalies produced were apparently dry, or at least 
contained no more moisture than might well be conceived 
to exist in the oxygene gas absorbed ; and their weights 
considerably exceeded those of the combustible matters 
consumed. 
The processes on which these conclusions are founded 
will be fully described hereafter, when the minute details 
which are necessary will be explained, and the proportions 
of oxygene, and of the respective inflammable substances 
which enter into union to form the fixed alkalies, will be 
given. 
It appears then, that in these facts there is the same evidence 
for the decomposition of potash and soda into oxygene and 
two peculiar substances, as there is for the decomposition of 
sulphuric and phosphoric acids and the metallic oxides into 
oxygene and their respective combustible bases. 
In the analytical experiments, no substances capable of 
decomposition are present but the alkalies and a minute 
