Alessandro Volta | autograph letter signed, to Canon Fromond, 12 August 1775

Volta, Alessandro

Autograph letter signed, to Canon Francesco Fromond

DISCUSSING HIS LATEST EXPERIMENTS WITH THE ELECTROPHORUS, explaining his use of wool to rub the resinous dielectric plate ("...vengo ora allo schiarimento che mi ricerca dello estinguersi l'elettricita del mastice col passarvi sopra leggermente un pezzo di lana. Dico dunque che si vuol questo accagionarne il peli, i quali rubbano colle lor punte l'elettricita: che cio sia vien suggerito de quest'altra prova, che si toglie egualmente ogni elettricita scorrendovi sopra con alcune sottili punte metalliche, ed anche non metalliche, come sarebbe con un fiocchetto de carta, con une spazzola ecc, ai fili della lana finissimi e infiniti piu presto e facilmente toccando tutti i punti della superficie elettrizzata ne li dispogliano..."), and his development of a mastic ("il mastice di mia composizione") which is more effective than tar ("asfalto") or wax ("la ceralacca") in producing an electrostatic charge, also promising to send Fromond a copy of his letter to Joseph Priestley on the eletrophorus, 2 pages, small folio, integral autograph address leaf with postal markings and trace of wafer seal, postmark, Como, 12 August 1775; edge-mounted in a collector's half-morocco folder by Alix, in a slip-off case

A LETTER WITH FINE SCIENTIFIC CONTENT DISCUSSING VOLTA'S FIRST MAJOR WORK ON ELECTRICITY. Volta's correspondent, Giovanni Francesco Fromond (1739-85), had been appointed a canon in his native Cremona in 1765 but his true interests lay in science. Fromond travelled widely in Europe and corresponded with many leading natural philosophers including Joseph Priestley and Benjamin Franklin. His friendship with Alessandro Volta developed in 1774-75 when Fromond was based in Florence, and he was also employed in the Brera Astronomical Observatory, which supplied instruments to Volta in Como. Volta's letter to Joseph Priestley on his invention of the electrophore, mentioned here, had been written on 10 June 1775 and was published later in the same year.

PROVENANCE:

Sotheby's, London, 21 November 1989, lot 404