Papers relating 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. 
e most decided results were obtained when the charcoa} 
points were connected in a small: glass tube; then the pro- 
jection formed on the negative pole with great rapidity— 
became half an inch or more in length, and a deep cavity was 
formed in the positive pole. It is impossible to doubt the ex- 
istence of a powerful current flowing froin 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 antag the walioenned state of the mat- 
oints. \.. 
In edicnating the changes of weight, the following circum: 
stances are to be taken into view. 
Volatile matter, iene aiiatiiane vapoee; &e. (drningie 
part from unavoidable reabsorption after the preparatory igni- 
tion) are expelled by the intense heat, and the carbon itself 
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 matter 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 in every instance, if we speak of its 
own A matter—but, as matter from ihe opposite sale 
accumulates upon the negative, this substance. is 
water just sufficient to restore the weight lost from the 
other causes, and at other times it is more than sufficient, thus 
causing 4 positive increase in weight. The reason why these 
facts are more observable in close vessels obviously is, 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, iss suggested by Dr. Hare,) still I suspect goes on 
in a. 
There appears to be little waste of the points, smcus 
where they are opposed, but considerable (and more consid- 
erable than I had sti supposed) on the laterally ane 
portions of the charcoal. 
oes the melted matter pocenelated. apes the negative 
pole consist in whole or in part of carb 
