ELECTRICITY AND LIFE. 161 
mals down, and it is necessary to avoid rivers frequented 
by the gymnotus, because, in attempting to ford them, 
horses or mules might be killed by the discharges. To 
capture these fish the Indians drive wild-horses into the 
water, stirring the eels up out of the mud by their tram- 
pling. The yellowish livid creatures press against the 
horses under their bellies, throw down the greater part, and 
kill some of them, but, exhausted in their turn, they are 
then easily taken with the aid of small harpoons. The say- 
ages employ them to cure paralysis. Faraday compares 
the shock of a gymnotus, which he had the opportunity to 
study, to that of a strong battery of fifteen jars. A live 
eel out of water, when touched by the hand, communicates 
a shock strong in proportion to the extent of surface in 
contact, and the stroke is felt up to the shoulder, and fol- 
lowed by a very unpleasant numbness. It may be trans- 
mitted through twenty persons in a chain, the first one 
touching the back, and the last the belly of the eel. The 
fishermen discover the presence of an eel in their nets by 
experiencing a shock in throwing pailfuls of water on, to 
wash them. Water is a good conductor, and this fish kills 
or benumbs the animals it feeds on by delivering a dis- 
charge through the water. 
Other sources of electricity are known to exist, besides 
thunder-storms and fishes. FF riction-machines, batteries, 
and induction instruments, yield three kinds of currents 
that act on vital functions, sometimes in a similar way, 
but oftener with marked differences, which have only re- 
cently been clearly distinguished. The action of static 
electricity, and that of electricity of induction, more sudden 
and violent, is particularly marked by mechanical effects so 
striking that they have long distracted experimenters from 
examining with due attention those effects of another sort, 
produced by the galvanic current. Yet the latter in reali- 
ty affects the animal tissues in a deeper way, and its re- 
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