ELECTRICAL ANIMALS. 
745 
walking, it is carried straight along the belly, trailing behind it with 
the point mp. When this creature is disposed to suck a part of a tree 
that is just before it, it draws up, and shortens the trunk, till it brings 
it to a proper length and direction ; but when it sucks in the common 
way, it crawls upon the inner surface of the bark, and the turned^ up 
end of the trunk, which resembles a tail, fixes itself against the wood that 
is behind it, or contiguous to its back, and sucks there. The extre- 
mity of this trunk holds so fast by the wood, that when it is pulled 
away, it frequently brings a small piece of the wood away with it. 
The ants are as fond of these as the other species of pucerons, and 
that for the same reason ; not feeding upon them, but on their excre- 
ment, which is a liquid matter of a sweet taste, and is the natural 
juice of the tree, very little altered- These creatures are the surest 
guides where to find this species of puceron, for if we at any time see 
a number of these ants crawling up an oak, and creeping into the 
clefts of the bark, we may be assured that in that place there are 
quantities of these oak pucerons. 
Animals which are endued with uncommon Electrical 
Properties. 
Not long after the discovery of the electrical shock, and the me- 
thod of augmenting the power of electricity, it naturally became an 
object W'ith electricians to investigate the effects of it upon animal 
bodies. These were quickly found to be entirely similar to such as 
are produced upon any other conducting substances, viz. an emission 
of sparks, attraction, repulsion, &c. By degrees it was found, that 
very strong signs of electricity were exhibited by some animals, even 
without the application of any artificial apparatus. The experiment 
of producing sparks by stroking the body of a cat in frosty weather, 
readily shewed that the electric fluid may exist in a very active state 
in the body of an animal, without injuring any of its functions. Mr. 
Cavallo says, that he has often observed, that, when stroking a cat 
with one hand, and holding it wdth the other, be felt frequent smart 
prickings on different parts of that hand which held the animal. In 
these circumstances very pungent sparks may be drawn from the tips 
of the ears of the cat.” He also mentions, “that by using a metal 
button fastened with a stick of sealing-wax, he can obtain such strong 
sparks from the back of a cat, a hare’s skin, a rabbit’s skin, &c. that 
he can presently charge a coated phial with either of these, and sO 
strongly as to pierce a hole through a card with its discharge.” 
From animals of the inferior kind, a transition was made to the 
human species ; and powers of electricity were discovered in them, 
W'here it had not been suspected before. Some persons have been 
remarkable for an extreme lustre of their eyes; and others have been 
so much electrified naturally, as to give evident signs of it when a 
sensible electrometer had been applied to them. Others have mani- 
fested an extreme sensibility of even the smallest degrees of electricity, 
insomuch that they would be affected by a flash of lightning, though 
so remote that the thunder could not be heard ; all this shewing, 
that the subtle fluid treated of, bears a very active part in the animal 
economy, led to more important researches on the subject. 
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