480 Scientific Intelligence. [JunE, 
explosion in the coal-mines presents to our view this fact, that 
though the inflammable gas comes into actual contact with the 
flame, and is kindled by it, yet the extension of the kindled air is 
infallibly obviated by the enclosure of the lamp in a cylinder of 
metallic gauze. This particular fact seems to establish this general 
truth, that flame cannot pass through tubes of small diameter—iron 
network being in fact a series of such tubes. Reflecting upon this, 
I was led to ask the question, Would not wire-gauze similar to that 
employed in the construction of the lamp, stretched across the aper- 
ture, through which the condensed gases in the reservoir of the 
oxy-hydrogen blow-pipe rushes into the pipe, confine any explosion 
which the reflux of the flame might occasion to the pipe itself, and 
thus completely ensure the safety of the operator, and the apparatus 
which he employs ? 
Conceiving the idea involved in the question not to be altogether 
destitute of plausibility, I was induced to make the following expe- 
riments, which, though necessarily rude, from the impossibility of 
procuring proper apparatus in a country town, seem yet to establish 
the proposition for the elucidation of which they were instituted. 
1 employed a tin tube of about six inches long and one inch in 
diameter, closed at one of its extremities. Having filled it with the 
gases in their requisite proportion, and put over the open extremity 
a lid of iron gauze, which had been previously made to adapt to it, 
] turned up the end which was in the water, and introduced it intoa 
vessel already filled with the same mixture of gases which the tube 
contained. This I exploded, and immediately plunged the tube into 
the water. I then took off the wire, raised it from the surface, and 
applied a taper. No explosion took place ; clearly evincing that all 
had exploded at the same time, and consequently that single gauze 
had produced no preventive effect. 
I then employed double gauze; and proceeding exactly in the 
same manner as in the first experiment, I found, after having ex- 
ploded the vessel in which the wired extremity of the tube was im- 
mersed, and having turned it down upon the water, that upon 
taking off the gauze, raising it from the surface, and applying a 
taper, an explosion was produced—apparently showing that the 
double gauze had prevented the communication of the flame. I 
repeated the experiment for a great many times, and in every in- 
stance obtained the same result. 
I conceived that in the mode of procedure now described this 
fallacy might occur: while the gauze was put on under the water, 
might not its apertures be filled with it, and thus prevent the passage 
of the gases through them? To obviate this, I did not put on the 
wire till the tube was raised from the water altogether. With this 
precaution, the result was the same as in the former case. 
Yet even here the passage of the gases in the tube, through the 
gauze, to the gases contained in the exterior vessel was not certain ; 
and thinking that were this circumstance ascertained nothing would 
be wanting to the certainty of the experiment, I had recourse to 
