Sbpti mi , 1842.] 211 



e ch the several copper shi i n the Medl nf the 



i her i* to ippose .1 1 . ti -heei* ol sheathing ei ppi 1 



pore coppei dep the galvanotype 1 



n ii 1 were exhibited in connexion wnh several i\ iih 

 nng copper, the specimens which had, by analysis, been shown u 

 le purest copper, exhibiting the highest electro-positive energy when 

 < im pared with platma.and ilie lowest electro-negative power when oppn.sed 

 lo the galvanotype plate. Composition nails were found near platina in the 

 scale, and galvanotype copper not so widely removed from iron as are some 

 varieties of brass. 



The arrangement of apparatus supposed to be best adapted for use in prac- 

 tice, is a triple astatic needle, having its middle needle w ithin, its lower one 

 below, and its tipper one above a spiral of copper ribbon, formed in such a 

 manner as to present the edges of the ribbon lo the upper and under surfaces 

 of the needles. The suspension may be either that of a pivot, or that of a 

 single or double support of unspun silk. The liquid preferred for use, in 

 tins species of lest, is ci minoti sea water; being the same to which practice 

 subjects the sheathins copper, and having the advantage ol being easily pro- 

 cured, costing nothing, and capable, therel re, ol being renewed as often a.-- 

 the operator may think' (it. 



MEETING FOR BUSINESS, September 27, 1842. 



Vice President Morton in the Chair. 



The Monthly Report of the Corresponding Secretary was 

 read and adopted. 



ELECTIONS. 



Jacob P. Giraud, Jr., E.-^., of New York, was elected a 

 Correspondent: 



And John Cassin, Esq., of Philadelphia, a member of the 

 Academy. 



