MO GYMN 
own exertion* the ele&ric matter,, fioce it no longer exifts 
in thofe which are Tick or dead. 5. That a motion of 
the mufcles is neceflary for the emanation of this mat¬ 
ter, efpecially of the mufcles o.f the hack; for, when 
tliefe are kept motionfefs by fqu.eezing the back, there 
is no (hock. 6. As the torpedo exhibits all tliefe phe¬ 
nomena, they niuft alfo arife from an animal electricity; 
which overturns all the hypothefes which have been 
imagined for its explication during two thoufand.years. 
This elettric property is ufeful to the fifli, both to pro¬ 
cure food, and to avoid its enemies. In the firft cafe, it 
fhins the fmaller fifh, and then devours them before 
they can recover themfelves; in the other, it can ftun 
the larger voracious kinds, and thus gain time to efcape. 
Mr. Hart link, in his Voyage to Guinea, part i. p. 144., 
obferves, that in thofe places where the eleClrical eel 
abounds, there are few or no other fifties to be found; 
and in thofe places the negroes and Indians are afraid te 
bathe. 
Though the matter we have brought forward fee-ms 
to prove the exigence of the elefiric fluid in this animal, 
yet many naturalifts have denied it, becaufe they never 
could difcern any fpark. Wallh, who, by his experi¬ 
ments made at Rochelle, proved the exiftence of elec¬ 
tricity in the torpedo, could not produce any fparks. 
Cavendifh endeavoured to fhew by experiments, that 
the Leyden phial might give fliocks with very weak 
fparks. This was not fuffieient, for a weak fpark was 
always perceptible ; and none could be feen in Walfh’s 
periments, though his torpedo was a very large one. 
After this, WalfhTent for electrical eels from Surinam; 
but they all died on the pillage, as well as thofe ordered 
by Mufchenbroek. In order to procure living ones, 
Wallh offered a handfome premium’; and he foon re¬ 
ceived in London four electrical cels all alive ; and in a 
letter which he wrote to Mr. LeRoi, (fee Rofier’s Jour¬ 
nal de Phifique, 1774,) it appears that hefuccecded in ren¬ 
dering thefparks vifible in the following manner : He placed 
a lea^f of metal on a circular piece of glafs; and then 
cut it in the middle ; on taking the fifli out of the water 
and irritating it, he faw the eleCtric fparks pafs from 
one half of the metal to the other. There is no reafon to 
doubt the truth of this experiment; for fir John Pringle 
and Mr. Magellan both allured Le Roi that they faw 
the paflage of the fparks, and that the experiment was 
repeated ten or twelve times with the fame refult. Mr. 
Magellan adds, that a company of twenty-feven perfons 
held hands and formed a circle; and, when the firft 
touched the eel, they all felt a fliock fimilar to that from 
the Leyden phial. The fparks, though more vifible in 
this than in the torpedo, are ftill fo fmall, that it is ne¬ 
ceflary to look through a magnifier towards the part 
whence the fpark is expected to proceed.—See the ar¬ 
ticle Electricity, vol. vi. p.433* 
This fifli is caught in nets; the fifliermen, when they 
have got a large one, immediately kill it with a club, to 
avoid the fliocks. At Surinam they preferve young ones 
in large tubs made on purpofe, feeding them with fmall 
fifli, or, when thefe are wanting, with earth-worms. In, 
ieCls they like beft, for they fwallow them with great 
avidity the inftant they are thrown in. As the {kin of 
this eel fecretes a deal of flimy matter, it is neceflary to 
change their water at leaf! every other day : the water 
is let°out by a cock, at the bottom of the veflel, and the 
fifli is fometimes left for feveral hours dry and motion- 
lefs; but, if touched at that time, the fliocks will be 
given as ftrong as ever. . 
Mr. Hunter gave the mufcles and nerves of this fifli 
in three plates, (fee Phil.Tranf. v.ol. lxv. plate 1, 2, 3.) 
Fermin found two kinds of mufcles; but we cannot con¬ 
clude that the direction of the mufcles in this fifli is pe¬ 
culiar to it alone, until more accurate difledtion and 
companion fliall have been made of other fillies of this 
genus. Cepede has a long account of the manner in 
OTUS. 
which, as he fays, the.ele&ric organs aft ; (fee his Hi ft. 
des Poiflons, ii. 162.) Nothing had been related refpeft- 
ing the inteftines and internal conformation, till Bloch 
diffe’fted one which was two feet and a half in length: 
the cavity of the lower belly was four inches long 4 the 
fkin was thick,, and hard like leather; the anus and ure¬ 
ter were not far.from, the chin ; they were carried along 
about an inch between the Ikin and the peritoneum be¬ 
fore they entered the abdomen. The gullet was wide, 
mufcular, and plaited or wrinkled. The ftomach formed 
a fac on the right fide ; it had feveral large folds, and 
the cardia and pylorus were clearly diftinguifliable, but 
no air-bladder could be difeerned. Some have fuppofed 
this fifli to have lungs, becatife it comes often to the 
fin-face to breathe ; but this is not the cafe. Such a 
fuppofition was for a time countenanced by fome obfer- 
vations of Dr. Garden, of South Carolina, who, at the 
requeft of Linnams, examined the organs of the genus 
Diodon, and found, as he conceived, both external 
branchiae or gills, and internal lungs. This idea, how¬ 
ever, has been (hewn by later phyfialogifts to have been 
not ftrlfily corredl; the fuppofed lungs being in reality- 
only a peculiar modification of gills. 
5. Gynmotus albifrons, the white-fronted gymnotus.. 
Specific cliara6ter, a fin at the end of the tail* a white 
band from the tip of the lower jaw to the middle of the 
back. There is only one ray to the membrane of the 
gills, 16 to the pedtoral fin, 147 to the anal, 20 to the 
tail. This is made a feparate genus by Cepede on ac¬ 
count of its having a tail-fin, which none of the gyin- 
noti have. He gives it a, name, aptcronotus, which fig- 
nifies the fame as gymnotus ; but, as it has no dorfal fin, 
there is no good reafon for feparating it. This fpecies 
has a very blunt fnout; the head has no vifible feales, 
but is full of pores which fecrete a vifeous. humour; 
the aperture of the mouth reaches beyond the eyes, 
which are covered by a nidlating membrane as in the 
reft of the genus. The noftrils are nearly midway be. 
tween the eyes and the tip of the muzzle. The lower 
jaw turns up at the tip, and has two other rifings, on 
each fide, which fhut into correfponding indentions in 
the upper. The gill-coverts are fattened al-mpft all round; 
the aperture is nearly femi-circular. The anus is fo near 
the head as to be placed in the angle which feparates 
the two branchial membranes,, near the point where they 
unite: behind the anus there is another orifice, fuppofed 
to give paflage to the fpawn and milt. The anal fin runs 
from the throat to the tail-fin, which accounts for the 
great number of rays it contains. 
What diftinguifhes this fifli from all others, is a long 
fleftiy filament or ftrap, which arifes about the middle of 
the upper furface of the fifli, (the head not included,) 
and runs loofe to the origin of the tail-fin, where it 
is faftened by its fmaller end. As there, is underneath it 
a kind of furrow on the back, Pallas, who firft remarked 
this peculiarity, thought that the fpecimen he was exa¬ 
mining had been cut up the back, fo as to leave a por¬ 
tion of the fkin faftened at the extremities only ; he was 
however afterwards convinced that it was a natural con¬ 
formation. Cepede has fince deferibed this part more 
accurately from a fpecimen in better prefervation brought 
from Holland to Paris. It is convex above, and concave 
underneath, and faftened by its larger end to the middle 
of the back ; it anfwers to a furrow, which le (Tens as the 
filament becomes thinner, as Pallas ©bferved; but he 
did not remark that it was again fattened by its fmaller 
end, clofe to the tail-fin; when raifed up, it fuftains ic- 
felf by its extremities, forming a bow, of which the tail 
is the firing; there are befides a dozen little threads 
ftretching from the furrow to the filament, like the rays 
of a fin when the membrane is taken away : thefe threads 
Hope towards the anal fin, and fall underneath when the 
large filament is let go into the furrow, which it fills up 
•entirely. This fpecies is of two colours, black, and the 
brighteH 
