Fusion of Plumbago. 34} 
tendant, on caloric, or = least in a greater degree, than on 
any other power 
It is extremely obvious, that, on all these subjects, we a 
still very humble learners; we may however, Seandemiy 
hope, that out of these diversified. results, and from others 
still to be obtained—some grand simplification will hereaf- 
ter arise, which will reconcile all ef cea: oe aoa facts, 
and perhaps evince, that all the imponderable influences 
are merely modifications of one oierecflnd they consti- 
tute the atmosphere, which connects physical existence with 
its author, and exhibit to us, in the natural world, the most 
immediate and wonderful efflux of his omnipotent energy. 
Your friend and servant, 
B. SILLIMAN. 
Art. XX.—Fusion of Plumbago. 
Notice of the Fusion of Plumbago, or Graphite, Seca | 
called black lead,) in a letter to Dr. Robert Hare, M. 
po the Editor, dated March 26, 1823. 
My Dear Sir, 
In a former letter published in this Journal, (Vol. V. pa. 
108,) and in an additional notice, (pa. 361 same Vol.) I gave 
an account of the fusion and volatilization of charcoal, by 
the use of your Galvanic Deflagrator. Ihave now to add, 
that the fusion of plumbago was accomplished de ten by 
the same instrument, and that I have, again ined t 
same results to-day. For this purpose, oa piece of 
fine and beautiful plumbago, from North-C arolina, T 
sawed small parallelopipeds, about one eighth of an inch in 
diameter, and from three fourths of an inch to oneinch and 
a quarter in length; these were sharpened at one end, and 
one of them was employed to point one pole of the deflag- 
rator, while the other was terminated by prepared char- 
coal. Plumbago being, in its natural state, a conductor, 
(although inferior to prepared charcoal,) a spark was read- 
ily obtained, but, in no instance, of half the energy which 
belongs to the instrument when in fall activity, for the zine 
coils were very much corroded, and some of them had fail- 
ed and dropped out; still the influence was readily convey- 
