253 



Mr. Vaughan informed the Society that Mr. Charles P. Fox, 

 who possessed a large collection of the original letters and 

 papers of Benjamin Franklin, had deposited them with the 

 Society. 



The Franklin papers were bequeathed, by will, to George Fox, 

 father of C. P. Fox, by Temple Franklin, grandson to Benjamin 

 Franklin, and by him submitted to Mr. Sparks, to aid him in the 

 completion of his edition of Franklin's works. Mr. Sparks recom- 

 mended Mr. Fox to deposit them with the Society, of which Franklin 

 was so long President. 



Dr. Hare made a communication respecting an extensive 

 voltaic apparatus, of the form which he had designated by the 

 name of galvanic deflagrator. This apparatus had been con- 

 structed for the Lowell Institute of Boston, under his direc- 

 tion, by request of Professor Silliman. 



It consists of four troughs, each containing 100 pairs within a 

 space of about 30 inches in length. The pairs, severally, are of the 

 Cruickshank pattern, and about 6| inches square, independently of 

 the grooves, so as to expose about 42 inches of zinc surface. Every 

 fifth plate is cemented into its groove by a compound of rosin and 

 suet. The plates, intermediate between those thus cemented, are 

 made to fit tightly into their grooves; but in consequence of a slight 

 obliquity in their sides, can be extracted by the aid of forceps, so as 

 to be cleansed, and, when expedient, scraped. The cementing of 

 each fifth plate tends to prevent any injurious retrocession of the vol- 

 taic fluid; and yet when the intermediate four plates are removed, an 

 interstice is vacated, sufficiently large to allow the stationary metallic 

 surfaces to be reached by a scraper. The plates are all amalga- 

 mated, which not only renders them less susceptible of wasteful 

 reaction with acid, but more susceptible of being cleaned. A strip 

 of wood, 13 inches wide and 2 inches deep, is bored by a centre 

 bit, so as to have eight vertical and cylindrical holes, which are all 

 supplied with mercury. By means of ropes of copper wire, these 

 holes are made to communicate severally with the poles of each of 

 the troughs, so that every one of these has its corresponding mercu- 

 rial receptacle. Arches of twisted copper wire are provided of such 

 various lengths, that the receptacles may be connected in such man- 

 ner as to cause the associated troughs to act either as one series of 



