Papers relaiing to the Fusion of Carbon. 123 
weight decidedly and rapidly, and always evinces a part of this 
loss by the cavity formed on the ignited point. The negative 
pole in the open air sometimes loses weight also, butin a much 
smaller degree than the positive pole. In close vessels the 
negative pole does not lose weight and it sometimes gains.. 
The most decided results were obtained when the charcoal 
points were connected in a smal! glass tube; then the pro- 
jection formed on the negative pole with great rapidity— 
became haif an inch or more in length, anda deep cavity was 
formed in the positive pole. [t ts :mpossible to doubt the ex- 
istence of a powerful current flowing from the positive to the 
negative pole. Wherever the projection on the negative 
pole was allowed to touch the opposite charcoal, the two 
strongly adhered, thus evincing the softened slate of the mat- 
ter on the points. . 
In estimating the changes of weight, the following circum- 
stances are to be taken into view. 
Volatile matter, hydrogen, aqueous vapour, &c. (arising in 
part from unavoidable reabsorption afier the preparatory igni- 
tion) are expelled by the intense heat, and the carbon itsely 
is probably exhaled in vapour, and when the air has access, 
some portion of it is burned, so that only a part (a part which 
will of course vary with circumstances) of the maiter lost by 
the positive pole can be expected to be found upon the neg- 
ative. The negative being subjected to similar causes also 
loses weight, probably tn every instance, if we speak of its 
Own proper matter—but, as matter from the opposite pole 
invariably accumulates upon the negative, this substance is 
sometimes just sufficient to restore the weight lost from the 
other causes, and at other times it is more than sufficient, thus 
causing a positive increase in weight. ‘The reason why these 
facts are more Observable in ciose vessels obviously 1s, that 
the air being in a great measure excluded, there is no waste 
by combustion, which, although materially obstructed by the 
extreme rarefaction of the air, and the vaporization of the 
charcoal, (as suggested by Dr. Hare,) stil} I suspect goes on 
in a degree. 
There appears to be little waste of the points, exactly 
where they are opposed, but considerable (and more consid- 
erable than I had formerly supposed) on the laterally ignited 
portions of the charcoal. 
Does the melted matter accumulated upon the negative 
pele consist in whele or in part of carbon ? 
