458 
had not succeeded in this country. The 
metallic nature of the earths will probably 
explain many facts in metallurgy and 
also in the natural history of our planet. 
In seducing metals from. their ores, some 
ef the earths are made use of as fluxes, 
and may probably affect the quality of 
the metals by uniting with them in a me- 
tallic state.* In the proces: of making 
malleable iron from cast iron, after heat- 
ing it for a long time, it is violently ham- 
mered, which separates from it a brittle 
ynetallic substance; this Dr. Davy said 
was the metal of silex combined with 
irdn ; but we were not informed by what 
means this fact had been ascertained, 
To the union of silex with iron, Dr, 
Davy ascribed the hardness and brittle- 
ness of castiron. There is a particular 
kind of steel manufactured in the East, 
which is so hard as to cut glass; some of 
this steel has been analysed, and is found 
to contain silex; hut whether in a me- 
tallic state, or the earth of silex, Dr. 
Davy did not mention, The earths be- 
ing metallic oxyds at the surface of the 
globe, is no proof that they may not 
exist in the metallic state in the interior 
ef our planet; and the experiments of 
Dr. Mackelyne on the density of the 
earth, agree very well with the supposi- 
tions Ibe whole globe is about four and 
one balf times as weighty as an equal bulk 
of water would be, and this is nearly the 
mean weight of all the metals. 
Were we to admit this supposition, 
Dr. Davy said, it would not be difficult 
to explain how volcanoes and earthquakes 
were produced. If a current of water 
should by any means find a passage and 
come in contact with any of the metals 
of the alkalies, or earths, they would in- 
stantly decompose the water, and absorb 
the oxygen; violent inflammation and 
explosions would take place, the metals 
united with oxygen would be thrown to 
the surface in the form of lava, earth, 
and mud. An experiment, giving a mi- 
niature representation of these effects 
was exhibited, in which potassium, lime, 
and iron were placed in the model of a 
mountain made of clay. On water being 
poured into a cavity or fessure in ‘the 
mountain, a violent combustion ensued, 
attended with vivid flames, and the erup+ 
tion of lava which run down the sides of 
the miniature volcano. In this manner 
also, we may conceive new continents to 
he raised according to some general law 
FSR RAT BO WET STA TEER eS 
* This cpinion we find was advanced by 
Baron Bern before the year i726. 
Proceedings of Learned Socicties. 
[June I, 
of nature, when the present mountains 
and continents are worn down and wash- 
ed into the sea. In the course of these 
lectures, Dr. Davy again adverted to the 
meteoric ‘stones which had fallen from 
the atmosphere. ~'These he supposed 
might he small bodies revolving round 
other planets, which came in contact 
with our atmosphere. The earths they 
contained, he said, probably existed in 
2 metallic state, and were inflamed and 
exploded by the oxygen or moisture 
which they met with in traversing the 
higher regions of the air. Of all the hy- 
potheses which have been formed to ac- 
count for these stones, we confess this 
appears the least probable. The prin- 
cipal] objection that was offered to these 
stones being formed by the explosion of 
inflamble gas, in which the metals were 
dissolved, was, that to form a stone of 
equal size and weight with the one which 
fell on Captain Topham’s estate in Yorke 
shire, would require 1000 cubic miles of 
gas. This objection does not appear to 
us of much weight. One thousand cubie 
miles of gas, if collected, would fill a 
sphere of rather more than twelve and 
one half miles in diameter, or a cube of 
ten miles. The meteor which passed 
over Europe én 1783, was stated to be 56 
miles above the earth, and to have a di- 
ameter and luminous tail 6 miles in ex- 
tent. 
If we suppose this inflammable metallic 
gas was extended in a stratum over all 
the countries where it was seen to ex- 
plode, the quantity of yas existing over 
any one place at the same time, would 
not be very great, compared with the 
space occupied by a stratum of clouds. 
The stones which have fallen in different 
parts of the world, are all composed of 
the same substances. Several of these 
stones were exhibited, That which fell 
in Yerkshire weighed 56lbs. those from 
France, America, and Ireland, were 
smaller, They were all coated with a 
black incrustation, when this was brokéw 
off the interior of the stones is of a light 
yellowish brown colour. They all con- 
tain silex and magnesia, with metallic 
particlés of iron and nickel, and some ins 
terspersed particles of iron pyrites. Se- 
veral specimens of meteoric iron were 
also exhibited; these contain iron and 
nickel, in combination; the nickel giving 
to the iron a degree of hardness which 
makes it very difficult to work. The nu- 
merous and well attested instances of 
the fall of these stones, which have oc- 
curred in our own times, leave no ee 
o¢ 
