232 Mr. Cooper’s Lamp Furnace, 
Art. V. Description of Mr. Cooper’s Lamp Furnace, for 
the Analysis of Organic Bodies. 
Havrine had occasion to use Mr. Cooper’s lamp for the analysis of 
organic bodies, described in the last volume of the Transactions of 
the Society of Arts, and having found it very effectual, we have 
taken the following account of it from that work, with an abstract 
of the method of using it; and are enabled by Mr. Cooper’s 
kindness to add the description of some improvements which he 
has since made on the original apparatus. 
Fig. 1. Plate iy. aa and 6 b, are two long spirit-lamps, each having 
ten burners and wicks, the burners of each lamp sloping towards 
those of the other, as seen in the end view, fig. 2. They are placed 
in a tin tray c c, mountedon four feet. This tray is perforated in the 
middle the whole length of the lamp, and as wide as ee, fig. 2. 
The object in sloping the burners is, that they may clear the lamps 
and approach each other as near as is requisite, yet leave free space 
for a current of air, the tray being perforated and mounted on feet 
for this purpose: dd are spring wires at each end.of the tray, 
to receive the tube ff containing the substance to be analyzed, and 
to hold it over the flames ; by pressing the shoulders g g, fig. 2, 
the wires open to receive the tube, and close on removing the pres- 
sure ; and should the tube be shorter than the lamps, an additional 
support on a leaden foot, fig. 3, is placed through the opening e ¢ 
of the tray to rise between the flames, and hold the end of the 
tube. 
The tubes are coated with copper foil, wrapped spirally round 
them ; if each succeeding fold be on half the other, there will be a 
double coat of copper all the way, if on two-thirds, there will be 
three layers of copper, by which the glass tube is prevented from 
bending when hot, and becomes very uniformly heated. The spi- 
rals are continued beyond the end of the tube to reach the support, 
and leave the end within the flames. The dotted line at A, fig. 4, 
shews the end of the tube short of the support, the foil is secured 
at the last coil by binding wire, as at ¢. 
