Fusion of Plumbago, 34 1 



tendant, on caloric, or at least in a greater degree, than on 

 any other power. 



It is extremely obvious, that, on all these subjects, we are 

 still very humble learners; we may however, confidently 

 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 apparently discordant facts, 

 and perhaps evince, that all the imponderable influences 

 are merely modifications of one power — that 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, 



Kotice of the Fusion of Plumbago, or Graphite, {commonly 

 called black lead,) in a letter to Dr. Robert Hare, M. D. 

 from 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. 36 1 same Vol.) I gave 

 an account of the fusion and volatilization of charcoal, by 

 the use of your Galvanic Deflagrator. I have now to add, 

 that the fusion of plumbago was accomplished yesterday by 

 the same instrument, and that I have, again, obtained the 

 same results to-day. For this purpose, from a piece of 

 very fine and beautiful plumbago, from North-Carolina, I 

 sawed small parallelopipeds, about one eighth of an inch in 

 diameter, and from three fourths of an inch to one inch 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 full activity, for the zinc 

 coils were very much corroded, and some of them had fail- 

 ed and dropped out; still the influence was readily convey- 



