372 PHILOSOPHY OF ZOOLOGY. 
this benumbing effort many times in succession in the water, 
as well as in the air, when arrived at maturity, and even pre- 
vious to the natural period of exclusion from the uterus of 
the mother. When caught in the net, it gives a shock to the 
hands of the incautious fisherman who ventures to seize it. 
When concealed in the mud, it is capable of making its 
most violent efforts; and is able to benumb the limbs to 
such a degree, as to throw down the passenger who inad-, 
vertently places his foot upon the body. 
Although the benumbing powers of the torpedo were 
known to Prato and Aristroti£, and had frequently been 
proclaimed by the verses of the poet, and the exaggerated 
statements of the fishermen, it was not until the doctrines of 
electricity had been established, that the circumstances un- 
der which these were exerted, and the effects which they 
produced, were investigated with any degree of success. 
The first person who turned his attention particularly to 
this subject, was Mr Watsu, and he succeeded in demon- 
strating, that the animal could exert its benumbing power 
at pleasure, and that the shock was regulated by all those 
circumstances which influence the discharge of the electric 
fluid from the Leyden phial ; in other words, he established 
the identity between the electric fluid and the benumbing 
power. His experiments were communicated to the Royal 
Society, July 1. 1773*. According to the experiments of 
this observer, the shock of the torpedo is prevented by all 
electrical non-conductors, as glass or sealing-wax ; while it 
readily passes along brass-wire, water, or persons whose 
hands are joined. The torpedinal fluid was unable to force 
itself across the minutest tract of air, or from one link of 
a small chain, suspended freely to another ; or through an 
almost invisible separation, made by the edge of a penknife 
* Phil. Trans. 1773, p. 461. 
