11 
df the fixed Alkalies. 
To be converted into vapour, it requires a temperature 
approaching that of the red heat ; and when the experiment 
is conducted under proper circumstances, it is found unaltered 
after distillation. 
It is a perfect conductor of electricity. When a spark from 
the Voltaic battery of 100 of 6 inches is taken upon a large 
globule in the atmosphere, the light is green, and combustion 
takes place at the point of contact only. When a small globule 
is used, it is completely dissipated with explosion accom- 
panied by a most vivid flame, into alkaline fumes. 
It is an excellent conductor of heat. 
Resembling the metals in all these sensible properties, it is 
however remarkably different from any of them in specific 
gravity ; I found that it rose to the surface of naphtha dis- 
tilled from petroleum, and of which the specific gravity was 
.861 and it did nGt sink in double distilled naphtha, the 
specific gravity of which was about .770, that of water, being 
considered as 1. The small quantities in which it is pro- 
duced by the highest electrical powers, rendered it very 
difficult to determine this quality with minute precision, I 
endeavoured to gain approximations on the subject by 
comparing the weights of perfectly equal globules of the 
basis of potash and mercury. I used the very delicate balance 
of the Royal Institution, which when loaded with the quantities 
I employed, and of which the mercury never exceeded ten 
grains, is sensible at least to the of a grain. Taking 
the mean of 4 experiments, conducted with great care, its 
specific gravity at 62° Fahrenheit, 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 
C 2 
