Safety- Furnace, €c. 3138 
We have thus provided another mean for obtaining an increased 
action. 
In referring to the apparatus [ have proposed for drawing off 
and consuming the explosive hydrocarbenate of the mine, I 
should have mentioned, that when one, two or more pipes are 
used, the orifices of the others must be shut by means of proper 
appendages. By allowing the urn to rest in water, it will always 
be kept cool ;—or a current of water being permitted to enter 
from below, through a small aperture ; we should have, besides 
the safety afforded by the wire-gauze, that of an atmosphere of 
steam ;—and if the position of Sir H. Davy be founded in truth, 
that flame is an exhibition of temperature above a white heat, 
and that the wire-gauze serves merely to cool down the flame below 
that increment which is the grade of incipient flame,—a fillet 
of wire-gauze iv the interior of the urn, thus, Mee ee 
would present a number of cooling surfaces, Aa 
by incepting the included flame, and such a ‘ 
convolute, or spiral partition of wire-gauze, 
would yield a security as ample and as abso- OY? 
lute as the safety-lamp*. ak ack 
I exposed to the action of the compound gases i in the oxy- 
hydrogen blowpipe, a fragment of a meteoric stone which fell at 
Pulrose (one mile from Douglas, Isle of Man), about twenty 
years ago, during a thunder-storm. It tore up the ground with 
considerable violence, killing a mare and foal at the same time. 
This meteorolite appears somewhat like a dark pumice-stone,— 
of low specific gravity,—and containing a few small white specks 
resembling deucite when exposed to high increments of tempera- 
ture. 
It exhibited before the blow-pipe: first, an intense most vivid 
light,—then entered into fusion, and passed into a Llack glass. 
I also introduced before the ignited gaseous mixture a piece of 
what has been Jong known here under the name of polishing 
powder. This portion of it which [ found in situ resembled 
asbestos, having a ligniform structure, but crumbling into a soft 
powder between the ‘fingers. 1 found it in contact with decom- 
posing granite and quartz interspersed with Tieedle schorl; in- 
deed, I have specimens which | found in the same place, com- 
posed of masses of needle and compact schorl exhibiting the 
various transitions into this substance. 
Before the blow-pipe it was characterized by a vivid light like 
*T apprehend that the convolute would present but one cooling surface, 
namely the exterior ; the inner convolutions would be in the situation of a 
piece of wire-gauze within a safety-lamp.—Ep:. 
magnesia 
