1817.] Scientific Intelligence. 481 
this expedient: having taken a tube nine inches long and one inch 
in diameter, with double gauze inserted in the middle, I filled it 
completely with the gases, oiled the gauze to prevent the adhesion 
of the water to its apertures, and closed both its extremities. Having 
then agitated the tube to make certain the passage of the gases 
through the gauze, I applied a taper successively to its ends, and 
found that each of them exploded; again demonstrating the pre- 
ventive effect of the gauze. 
So far have these experiments been successful ; and it is not in 
my power, while in the country, to extend them by their applica- 
tion to the blow-pipe. They seem, however, in some degree, to 
warrant the success of such an application. 
Since the good effect of Sir H. Davy’s arrangement depends 
upon the perfect construction of the cylinder, to render their appli- 
cation to the blow-pipe not only safe, but simple, the gauze might 
be adjusted to the pipe, and not to the reservoir, to which it might 
be made to fix with a screw, and in this way be examined every 
time before commencing the operation. 
Kelso, April 24, 1817. G. Gray. 
Il. Further Improvement in the Oxygen and Hydrogen Blow-pipe. 
(To Dr. Thomson.) 
DEAR SIR, April 18, 1817. 
Necessity, ever prompting the ingenious to further inquiry, in- 
duced Dr. Clarke, from the suggestion of Dr. Wollaston, to form 
the fagot of capillary tubes for the passage of the mixed gases to the 
jet. Struck with the ingenious contrivance, it immediately occurred 
to me that some time since, having occasion to distil some acetic 
acid, and not having proper apparatus by me at the time, I made 
use of a Florence flask, connected with a receiver by a piece of bent 
cane, and found it answer iastead of a tube beyond my expectation, 
which suggested to me the idea of introducing cane, or any other 
wood sufficiently porous, instead of the brass capillary tubes, for the 
passage of the gaseous mixture ; or instead of cane, suppose a fagot 
of very small steel or iron wires made taught by driving in a 
stronger one, the space between the wires being as so many capil- 
lary tubes. I drove a piece of cane 14 inch long and one inch 
diameter into a brass cylinder, in connection with a gaseous blow- 
pipe, and found the gases pass with the greatest facility. I consider 
the methods above proposed will obviate the difficulties that may 
occur in procuring tubes sufficiently small. 
I beg leave to propose the following queries :— 
1. May not the phenomena exhibited by the gaseous blow-pipe 
be analogous to that produced by a galvanic battery, the oxygen and 
hydrogen disengaged at the negative and positive ends being ignited 
by electricity ? 
2. Having heard that oxygen gas is often conveyed to a distance 
in bottles, I think it might be more profitably done by condensing 
it into a strong metal vessel previously exhausted, By this means a 
Vor. 1X. N° VI. 2H 
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