[ ”7 ] 
and many others of this Clafs. I have covered at 
one time the Cufhion, with which I rubbed a Globe, 
with eight Lamina of Sheet-Lead, and have ex- 
cited Electricity from that Metal: And however 
improper a Deal-Board may fecm for the Purpofe 
of rubbing a Globe, I have more than once ac- 
cumulated Electricity from that, though its Sub- 
ftance has the Appearance of being much lefs fit 
than every one of the Originally-Eledtrics I men- 
tion’d before. 
§ XXV. To the Do&rine here laid down it may 
be obje&ed, that Leather is an animal Subftancc, 
which, though perfe&ly dry, excites Ele&ricity the 
ftrongeft of all the Subftances hitherto difeover’d s 
that dry Leather ought to be confider’d as an Origi- 
nally-Ele&ric 5 and therefore, according to the Rule 
before-mention’d, fhould not furnifh, from rubbing 
the Globe therewith, any Ele&ricity at all. To this I 
anfwer,that though the dry Skins of Animals are Elec- 
trics per fe,d ry Leather is far from being fo; and this 
is owing to the vaft Quantities of reftringent vegetable 
Subftances imbibed by the Skins throughout their 
whole Contexture in the Operation of Tanning in 
fome Species of Leather, and of faline Subftances, 
fuch as Alum, in others 5 both which Subftances arc 
non-ele&ric, and of thefe Leather very confidera- 
bly partakes : For by thefe the Hides and Skins of 
Animals (and any Mufcle of their Bodies is liable 
to the fame Treatment), which otherwife areas pu- 
trefeent as any Part of their Bodies foever, are made 
to laft through many Ages, and be fubfervient to 
, many 
