126 Papers reiading to the Fusion of Carbou. 
and vigorous limbs—sawing it into cylinders of convenient 
size, and igniting it thoroughly, ina blaek lead pot,* covered 
by another of the same kind—the whole being placed in a 
powerful wind furnace. Other pieces of the same kind of 
charcoal were treated in the same manner, after being pre- 
viously boiled in distilled water, or in diluted muriatic acid, 
the object of which obviously was to remove alkaline, fer- 
yuyinous. or other soluble impurities. J may observe, once 
for all, that there appeared to be no difference in the sensi- 
ble phenomena attending the experiments or in the results, 
whether one kind of charcoal or another was employed, or 
whether it had been boiled with acids and water or not : af- 
ter boiling, it was always re-ignited in the furnace, before it 
was used in the deflagrator. 
A leading objeci of the experiments now to be stated, was 
to ascertain whether there was any change of weight in the 
ignited charcoal. 
March 4th, 1825, charcoal being used, which had been 
boiled in weak murtati¢ acid, afterwards in distilled water, 
and finally ignited intensely in close vessels in the wind fur- 
nace. 
I ought perhaps to mention that the deflagrator formerly 
described, had been enlarged by the addition of eighty of the 
compound coils suspended on two parallel beams and dip- 
ping into their appropriate troughs ; thus the surface of meta! 
was doubled, and the power of the instrument very consid- 
erably increased. No difference however was observed in 
the phenomena, exceptin the rapidity and energy with which 
they were produced. It should also be observed that the 
word positive here refers to the zinc, and the word negative 
to the copper pole. These terms having been erroneously 
applied, when the instrument was first invented, and the error 
not being discovered until after my former experiments were 
published ; the designation of the poles is therefore oppo- 
site, in these remarks, to that employed in the former papers. 
i. The points of charcoal were instantly fused, with a 
crackling of the charcoal, the result exactly resembling he- 
matite—the projecting cone or cylinder being formed rapidly 
on the negative, while a corresponding cavity was produced in 
the positive charcoal. 
2. The same. 
ee eee 
* No sand was used to cover the pieces. 
