[mail Quantities of Electricity. 3 
origin, or very beginning, ought to be inveftigated, it being 
afterwards very enfy to underftand its increafe ; for we may 
eafily comprehend, how a great quantity of it may be accu- 
mulated from the often repeated additions of its fmalleft 
portions. 
This truth having been under flood by feverai philofophical 
per fons, has induced them to contrive infhuments neceffary 
for the purpofe, and to make numerous obfervatlons, which 
have undoubtedly promoted the knowledge of the fubjeCt ; but 
a great deal flill remains to be done, before we can attain to 
the knowledge of the object in view, viz. of the real nature, 
of the firft origin, and of the general ufe of electricity. The 
inftruments hitherto invented are ftill inadequate to the pur- 
pofe, and the known methods of operating are not free from 
confiderable objections. To examine the peculiar conltruc- 
tions, intended ufes, properties, and defeCts, of thofe inftru- 
ments, as well as methods of performing the experiments, is 
the principal objeCt of the prefent LeCture, which I have the 
honour of delivering to this learned Society, and which may, 
perhaps, be of ufe to other experimenters in this branch of 
philofophy ; fince what is mentioned in the following pages is 
the refult of long experience, and of confideration. Of expe- 
rience, which has often contradicted the fanguine expectations 
of a pre-conceived theory; and of confideration, which has 
frequently demonftrated the abfurdity or infufficiency of 
fchemes which, at firft fight, feemed very eafy and plaufible. 
The late Mr. John Canton was, as far as I know, the 
firft perfon who conftruCted an electrometer, or inftrument 
capable of (hewing the prefence of what was then confidered 
as a fmall quantity of eleCtricity. This inftrument confifted 
of two fmall balls of pith of elder or of cork, fattened to the 
B 2 two 
