406° Miscellanies. 
upper or receiver plate of the electrophorus, be placed upon it and 
touched, it will evince a very vigorous action on the electroscope. 
“'This effect may be increased by the use of the condenser, and 
_ even a common Leyden jar may be charged in favorable weather to 
a considerable degree of intensity. 
“By asingle contact of the plate of this electrophorus ‘so nar 
electricity is sometitnes developed, that it will communicate to a pin’s 
head, electricity enough to turn the small needle of the silk thread 
torsion balance through two or three revolutions. 
“The non-conducting property of caoutchouc may be profitably 
employed in the construction of torsion balances, for measuring the 
intensity of electrical action. For this purpose a string of the gum, 
convenient thickness, may be cut froma sheet or bag, making 
‘as neatly as practicable of uniform thickness. This may after- 
wards be reduced to the required size by ‘treating it with ether, 
' aa. it and allowing it to remain distended: until the ether is 
es A small longitudinal hole may then be made at 
er ugh whic a needle of gum shellac, ¢ ying a disk of 
‘al, or’ ra is’ Pa very thin spherical bag “caoutchouc at 
one extretay, ‘may be accurately adjusted on its centre of gravity: 
Insulators of this substance may be formed either in plates, strings, 
or conical portions of bags to support any required apparatus. 
“ Hence it appears that nearly a complete set of electrical appara- 
Fas may be formed of this substance, capable of being transported 
with perfect ease and safety under circumstances in which the com- 
mon apparatus would be inevitably demolished. In a large bag, or 
_ extended sheet, it may be used for the-cylinder or plate of the com- 
"mon machine. A portion ef the same may be substituted for the 
! The electrophorus, the condenser, a _ e Leyden jar 
formed of it. The torsion balance co ed with balls of 
substance instead of pith balls, is an instrument far preferable to 
oa of Cou mb. Thi jo nay receive either the coiled form al- 
ready d d, or it may have the usual form by making the inner 
‘coating of finned iron, covering it sees a thin sheet of gum, and then 
efsing an exterior coating of metal. 
4, Ritooical remarks relating e Mexico, §c. in a letter dated 
Mexico, May 30th, 1830, from Wiuuram Macuure, Esq. —The 
regular order of origi nal § ratification has been so much deranged in 
this country by the intimate-and frequent alternation of voleanic 
rd LI 
a 
