eB 
A. — Nolices respecting New Books. 139 
_*© The cotton moistened. with sulphuric ether (the most in- 
flammable liquid known), subjected to the like experiment, was 
not ignited: but as the ether oozed a little through the gauze, 
voth in a liquid state and in the state of vapour, it became feebly - 
inflamed at the under part of the cloth: the cotton, however, did 
not tuke fire till the gauze was quite red, which did not take 
place tili after the lapse of some minutes, and often after the 
evaporation of the ether. 
“< | have exposed successively a wire gauze of iron, a gauze 
of brass, a piece of tinned iron pierced with holes of the size of 
poth of an inch, and an iron plate pierced with similar holes, be- 
tween alighted candle and a current of gas issuing from the cock 
of a reservoir (gasometer) full of carburetted hydrogen gas: the 
gas was soon inflamed by the light of the candle, on the other 
side of these diaphragms, without any communication of the 
flame taking place between the cock and the diaphragms of iron 
wire-gauze and pierced iron-plate ; but afteracertain time, the 
gauze of copper and the pierced white-iron could no longer pre- 
yent the communication of the fame between the two sides, and 
that because the heat was become sufficient to burn the zinec*, 
which is united to the red copper in the brass, and the tin which 
covers the iron in the white-iron-plate. ' 
‘* The gauze of iron-wire placed between a current of inflamed 
carburetted hydrogen gas, and a current of the same gas not in- 
flamed, both directed to the same point, has never permitted the 
communication of the inflammation to the cold gas, however 
long the experiment may have been continued. This experiment 
is the same as that which takes place when the safety-lamp is 
set in the midst of an atmosphere of detonating mixture; with 
this slight difference, that in the latter, every current of gas 
presses much stronger upon the gauze than when the gas is at- 
tracted into the interior of the lamp to replace that which has 
been absorbed by the combustion, 
| have only reported these experiments in order to demon- 
strate that it is indispensable that the gauze be of iron-wire ft, and 
; 
d 
, 
* « The zinc at the moment of being inflamed became volatilized to the 
gtate of white oxide. The same thing happened at the sitting of the Chamber 
of Commerce of Mons, on the 28th of January 1818, in presence of a num- 
ber of coal-proprietors. A current of inflammable gas, distilled from coal, 
haying been directed for a long time upon one point of a safety-lamp, the 
gauze of which was of brass wire, it heated that part of the gauze to such 
a degree, that the zirc took fire, and communicated the inflammation to 
the gas between the lamp and the orifice of the cock of the vessel which 
contained the gas—an inconvenience which there is no fear of encountering 
when the gauze is of iron wire. 
+ Pure copper wire will answer equally well, as it is only the presence 
pf zinc in brass wire which renders this improper.—T, ; 
/ ’ Qo 
