6 Mr. Davy’s Lecture on the Decomposition and Composition 
greater intensity of action in the batteries, or the alkali was 
required to be in much thinner and smaller pieces. With the 
battery of 100 of 6 inches in full activity I obtained good 
results from pieces of potash weighing from 40 to 70 grains, 
and of a thickness which made the distance of the electrified 
metallic surfaces nearly a quarter of an inch ; but with a 
similar power it was impossible to produce the effects of 
decomposition on pieces of soda of more than 15 or 20 grains 
in weight, and that only when the distance between the wires 
was about 4 or — of an inch. 
The substance produced from potash remained fluid at the 
temperature of the atmosphere at the time of its production ; 
that from soda, which was fluid in the degree of heat of the 
alkali during its formation, became solid on cooling, and ap- 
peared having the lustre of silver. 
When the power of 250 was used, with a very high charge 
for the decomposition of soda, the globules often burnt at the 
moment of their formation, and sometimes violently ex- 
ploded and separated into smaller globules, which flew with 
great velocity through the air in a state of vivid combustion, 
producing a beautiful effect of continued jets of fire. 
III. Theory of the Decomposition of the. fixed Alkalies ; their 
Composition, and Production. 
As in all decompositions of compound substances which I 
had previously examined, at the same time that combustible 
bases were developed at the negative surface in the electrical 
circuit, oxygene was produced, and evolved or carried into 
combination at the positive surface, it was reasonable to con- 
