[ vi; i 
II. Of the Method of rendering very fenfible the weahejl Natural 1 
or Artificial ’Electricity. By Mi'. Alexander Volta, Profejfbr 
of Experimental Philo fophy in Como, 13c. 13c . ; communicated 
by the Right Hon . George Earl Cowper, F. R. S. Seep. 23 ^ 
PART I. 
1 . TT will be readily allowed, that an apparatus capable of 
X rendering, perceptible, or, as it were, of magnifying the 
fmalleft, and otherwife unobfervable, degrees of natural as well 
as artificial electricity,, is of great advantage to the fcience of 
eleCtricity in general, and dpecially for the inveffigation of 
atmofpherical eleCtricity, which by this means may be ren- 
dered very lenlible and conlpicuous when it is not to be diico- 
vered by common atmofpherical conductors. This method is 
founded upon a particular life of my eledtrophorus , which is a 
machine well known to eleCtricians. 
2 . Whenever in obferving the atmofpherical eleCtricity no 
degree of it can be difcovered by the ordinary methods of per- 
forming thofe experiments, it is difficult to determine whe- 
ther any eleCtricity at all does or does. not exift in the atmo- 
fphere at thofe times ; fmce it may exift, and the quantity of 
it only be fo fmall as not to affeCt the electrometers employed.. 
An ordinary conductor, ereCtcd in. the belt manner for the pur- 
pofe of obferving the atmofpherical eleCtricity, when the Iky is 
free from eleCtrical clouds, feldom or never fhews any figns 
of eleCtricity. In that cafe, therefore, if we rely upon the 
common electrometers, even the molt feniible, we mult con- 
clude, that neither the conductor nor the atmofphere, fo high 
as the conductor reaches, contains any eleCtricity ; but by 
means of the apparatus I am going to defcribe, it will be 
found, that the faid conductors are never entirely void of elec- 
, tricky „ 
