1809. ] { 2a) 
PROCEEDINGS OF LEARNED SOCIETIES. 
EE . 
ROYAL SOCIETY OF LONDON, 
E have in different parts of the 
last two or three volumes of the 
Mouthly Magazine, given an account of 
the discoveries made by Mr. Davy; these 
accounts being frequently taken from 
memory, by a person who has diligently 
attended the lectures of the Royal Insti- 
tution, weuld necessarily be imperfect. 
We intend, therefore, in this and some 
subsequent articles to lay before our rea- 
ders a nore exact analysis of what has 
been done by this learned professor, and 
in the order in which he communicated 
the same to the Royal Society of Lon- 
don. Mr. Davy first described the me- 
thods made use for the decomposition of 
the fixed alkalies; and he found that 
the powers of electrical decomposition 
were proportional to the strength of the 
opposite electricities in the circuit, and 
to the conducting power and degree of 
concentration of the materials employed. 
In his first attempts at the decomposition 
of the fixed alkalies, he acted uponaque- 
ous solutions of potash and soda, satura- 
ted at. the common degrees of tempera- 
ture, with the Voltaic batteries, but in 
these cases; the water alone was affected, 
and hydrogen and oxygen disengaged 
with the production of much _ heat, and 
violent effervesence. As water appear- 
ed to prevent the decomposition, he used 
potash in igneous fusion, and some bril-’ 
liant phenomena were produced; and 
when the platina spoon, on which the 
potash was placed, was made to commu-~ 
nicate with the negative side of the bat- 
tery, and the connection from the posi- 
tive side was made with platina wire, a 
vivid and constant light appeared at the 
Opposite point: there was no effect of 
inflammation round.it; but aériform bub- 
bles, which, inflamed in the atmosphere, 
rose round the potash. He made some 
attempts to collect the combustible mat- 
ter, but without success ; and he only at-. 
tained his object, by employing electrici- 
ty as the common agent of fusion and 
decomposition. 
Pat-ash, when perfectly dried by igni- 
tion, is a non-conductor; but with the 
slightest addition of moisture, becomes 
a good conductor, and in this state it 
readily fuses and decomposes by strong 
electrical powers. Having placed a 
small piece of pure pot-ash, on an insu- 
Jated disk of platina connected with the 
negative side of the battery, and a pla. 
tina wire, communicating with the posi-. 
tive side, being brought im contact with 
the upper surface of the alkali, a vivid 
action almost instantly took place; the 
pot-ash fused at both points of electrizas. 
tion: there was a violent effervescence 
at the upper surface; at the lower, or 
negative surface, there was no liberation 
of elastic Muid; but small globules having 
a high metallic lustre, similar, in visible 
characters, to mercury, appeared ; some 
of which burnt with explosion and bright 
flame, as soon 2s they were formed, and 
others remained, and were merely tar- 
nished, and finally covered with a white 
film, which formed on their surfaces. 
‘‘ These glabules,” says the professor, 
“ numerous experiments soon shewed to 
be the substance I was in search of, and 
a peculiar inflammable principle, the oa- 
sis of pot-ash.” He ascertained that 
the platina was not at all connected with 
the result, for the same substance was 
produced when other metals, or char- 
coal, were employed for completing the 
circuit. 
Soda, when acted upon in a similar 
manner, exhibited an analogous result, 
but it required a battery of stronger pow- 
ers. The substance produced from pote 
ash, which is now denaminated “ Poe 
tassium,” remained fluid at the tems 
perature of the atmosphere, at the ttme 
of its production: that from soda, called 
“¢sodaum,” which was fluid, in the de~ 
gree of heat of the alkali, during its for- 
mation, became solid on cooling. The 
globules often burnt at the moment of 
their fermation, and sometimes violently 
exploded and separated into smaller glo= 
bules, which flew with great velocity 
through the air,in a state of vivid combuse 
tion, producing a beautiful effect of conti~ 
nued jets of fire. 
In speaking of the theory, Mr. Davy 
observed, that the metallic lustre of the 
substance from potash, immediately be- 
came destroyed in the atmosphere, and 
that a white crust formed upon it. This 
crust is pure potash, which immediately 
deliquesced, and new quantities were 
formed, which in their turn, attracted 
moisture from the atmosphere, till the 
whole globule disappeared, andassumed 
the form of a saturated solution of pot- 
ash. Water is likewise decomposed in 
the process ; for it is demonstrated that 
the basis of the fixed alkalies, that is, 
“* Potassium” and ‘“ Sodaum,” act upon 
this 
~ 
