104 CHEMICAL AND PHARMACEUTIC MANIPULATIONS. 
diaphragm c. The gas pipe of flexible lead depending from, 
and connected by a gallows screw A, with the permanent 
hanger o, terminates in an Argand burner d. To prevent a 
scorching of the table, the burner and cylinder both rest 
upon a fluted plaster tile. The air enters through the open- 
ings in the lower circumference, being drawn up by the up- 
ward current of gas, which is let on and regulated by the 
stop-cock r ; and the mixture thus formed passing through 
the upper fine wire gauze, above which it is ignited, should 
burn with a bluish flame. 
" Where the quantity of gas is too great for the amount 
of air admitted, the flame will be white and smoky, but by 
regulating the supply of gas, the due proportion for a blue 
flame will be easily attained. Now, to attain a blue flame 
from a cylinder of large diameter, a considerable quantity 
of gas will be requisite, and hence an economical advantage 
s gained by employing cylinders of different diameters. 
In the same cylinder, also, where different quantities of heat 
are desired, the lower series of holes may be made large, 
and a ring of sheet-iron slid over them, by which the quan- 
tity of air admitted or regulated according to the quantity of 
gas consumed. The cylinders may be 2§ to 5 inches diam- 
eter by 6 — 8 inches in height ; but by introducing several 
pieces of coarse gauze, c, at short distances apart, the height 
Fig. 3. 
cylinder of sheet copper, 
stretched over the top of 
i which, and fastened by an 
iron hoop, is a fine wire 
gauze, covered with fine 
jj gravel to protect it from 
I wear and tear. In order to 
promote a more thorough 
A admixture of the gas and 
atmospheric air, (which is 
^ affected in the chimney,) 
there is a coarse wire gauze 
