372 On purifying Coal- Gas. 
To give your readers a perfect idea of my stove, which might 
not unaptly he called a Thermophotogen, would be impossible 
without a plate, for which there is not now time, as I could wish 
this notice of Mr. Parker’s paper to appear in your next number. 
—Sutffice it to say, that the body of the stove is an upright cy- 
linder of east iron, standing four feet high, rather conical, being 
ten inches diameter inside at the top, and twelve inches at the 
bottom. For the sake of portableness, and to ensure against ex- 
pansion, it is divided into three separate pieces. First, an ashpit 
eight inchés deep, having a docr in its side to regulate the 
draught : second, the part one foot eight inches high contain- 
ing the door through which fuel is introduced, and opposite 
to which is an aperture to receive an iron cylinder or gun-barrel : 
and thirdly, the part in which at its sideis placed the flue. The 
parts fit in proper order one upon another, having the joints co- 
vered by a small plinth ; the top is open, through which is placed 
a cylindrical retort of two feet six inches long, and seven inches 
diameter, its flanch forming a top to the stove and covering the 
flue, which_the difference of the diameter of the retort and that 
of the interior of the stove allows. Itis evident, that if the body 
of the stove be now inclosed with a light sheet iron carcase, 
leaving a hot air flue all round except at the doors, the heat 
given off by the stove may be conveyed into apartments ; at the 
same time that its internal heat is liberating the gas in the retort. 
The cap of the retort is on the simplest construction, like that 
of the common culinary digester, only fitted with a plug and 
socket by which the gas is conveyed through a cylinder contain- 
ing iron turnings, &c. after which it passes through lime-water 
or not at pleasure. This method requires very little fuel, serves 
two purposes, and makes very pure gas. The scale upon which 
the foregoing apparatus is constructed may be said to be but 
small, though amply large enough for the majority of families ; 
yet it proves sufficiently that its principle is calculated to obtain 
every advantage reasonably to be hoped for. First, a very great 
increase of gas is obtained from a given quantity of coal, in com- 
parison to the old method, in which the essential oil, the tar, and 
the water of crystallization are all condensed prior to washing : 
but by passing through iron turnings, or any oxidizeable surfaces, 
the two first are nearly all converted into gas, and.come even 
with the hydrogen of the latter, which has been liberated at the 
expense of the iron turnings.—It is evident, the great increase 
arises infinitely more from the decomposition of the water than 
of the tar, which | am afraid Mr. Parker’s tubes alone after a 
short time will fail to do. Secondly, the nuisance creating sul- 
phuretted hydrogen is perfectly decomposed, as well as the car- 
bonic acid and ammoniacal gases. And last, though not least 
in 
