POT^SIUM. 
bago, or even charcoal, were employed for 
completing the circuit.” 
Soda, when acted upon in the same man- 
ner, exhibited an analogous result, and these 
effects equally took place in the atmos- 
phere, and when the alkali was acted upon 
in the vacuum of an exhausted receiver; 
but these globules could not in either case 
be produced from crystallized alkalies. 
When a globule of the base of potash was 
exposed to the atmosphere, it immediately 
attracted oxygen, and a white crust formed 
upon it, which proved to be pure potash. 
When the globules were strongly heated 
and then suspended in oxygen gas, a rapid 
combustion with a brilliant white flame was 
produced, and these metallic globules were 
converted to an alkali, whose weight great- 
ly exceeded that of the combustible matter 
consumed. Wlien Mr. Davy had thus de- 
tected the basis of the fixed alkalies, he 
had considerable difficulty to preserve and 
confine fhem, so as to examine their pro- 
perties atid submit them to experiments. 
He found, however, at length, that in re- 
cently distilled naphtha they may be pre- 
served many days, and that their physical 
properties may be easily examined in the 
atmosphere, when they are covered by a 
thin film of it. The basis of potash, at 60“ 
Fahrenheit, is only imperfectly fluid; at 
70“ it becomes more fluid ; and at 100“ its 
fluidity is perfect, so that different globules 
may be easily made to run into one. At 
50“ it becomes a soft and malleable solid, 
which has the lustre of polished silver; and 
and at about the freezing point of water 
it becomes harder and brittle, and when 
broken in fragments exhibits a crystallized 
texture, of perfect whiteness and high me- 
tallic splendour. To be converted into 
vapour, it requires a temperature approach- 
ing that of tlie red heat. It is an excellent 
conductor of heat, and a perfect conductor 
of electricity. 
Resembling the metals in all these pro- 
perties, it is, however, remarkably different 
from any of them in specific gravity ; for it 
will not sink in double distilled naphtha, 
whose specific gravity is only .770, that 
of water being considered as l.ObO. Mr. 
Davy has determined by experiment that 
its specific gravity is to that of mercury as 
10 to 223, which gives a proportion to that 
of water nearly as 6 to 10 ; so that it is the 
lightest fluid body known. Wlien this sub- 
stance is introduced into oxymuriatic acid 
gas, it burns spontaneously with a bright 
red light, and muriate of potash is formed. 
When thrown upon water, it decomposes 
it' with great violence, and an instantaneous 
explosion is produced with brilliant flame, 
and a solution of pure potash is the result. 
When a globule is placed upon ice, not 
even the solid form of the two substances 
can prevent their union ; for it instantly 
burns with a bright flame, and a deep hole 
is made in the ice, which is found to con- 
tain a solution of potash. When a globule is 
dropped upon moistened turmeric paper, it 
immediately burns, and moves rapidly upon 
the paper, as if in search of moisture, leav- 
ing behind it a deep reddish brown trace. So 
strong is the attraction of the basis of pot- 
ash for oxygen, that it discovers and decom- 
poses the small quantities of water contain- 
ed in alcohol and ether, even when they 
are carefully purified. When thrown into 
the mineral acids, it inflames and burns on 
the surface. In sulphuric acid, sulphate of 
potash is formed ; in nitrous acid, nitrous 
gas is disengaged, and nitrate of potash 
formed. When brought in contact with 
a piece of phosphorous, and pressed upon, 
there is a considerable action : they be- 
come fluid together, burn, and produce 
phosphate of potash. When a globule is 
made to touch a globule of mercury about 
twice as large, they combine with considera- 
ble heat ; the compound is fluid at the tem- 
perature of its formation : but when cool it 
appears as a solid metal, similar in colour 
to silver. If this compound be exposed 
to air, it rapidly absorbs oxygen ; potash 
which deliquesces is formed ; and in a few 
minutes the mercury is found pure and un- 
altered. 
When a globule of the amalgam is thrown 
into water, it rapidly decomposes it with 
a hissing noise, potash is formed, hydrogen 
disengaged, and the mercury remains free. 
The basis of potash readily reduces metallic 
oxides when heated in contact with them. 
It decomposes common glass by a gentle 
heat, and at a red heat effects a change 
even in the purest glass. Mr. Davy has 
discovered that its base, like that of potash, 
is white, opaque, and has the lustre of silver. 
The property of w'elding, which belongs to 
iron and platina, at a white heat only, is 
possessed by this substance at common tem- 
peratures. It is very similar, in its more ob- 
vious properties to the base of potash ; but 
it has greater specific gravity, being to that 
of water nearly as nine to ten, or as .9348 
to 1.0000. In oxygen gas it produces a 
white flame, and sends forth bright sparks, 
occasioning a very beautifnl effect. In 
oxy-muriatic acid gas it burns vividly, with 
numerous scintillations of a bright red 
