40 Voltaic Induction. 
shock is not at all in proportion to the intensity of the current; for 
the second arrangement which affected the galvanometer to the ex- 
tent of 70°, gave scarcely any sensation to the tongue; whereas that 
in, fig. 6, hardly moved the needle of the galvanic multiplier and yet 
occasioned shocks as disagreeable as those produced by an active 
galvanic battery of fifty plates, four inches square. I do not think 
that the distinctions of intensity and quantity will solve the difficulty ; 
for, if the want of action upon the galvanometer and the power of 
giving shocks, be owing to the passage of a fluid, great in quantity 
but of weak intensity, then we should expect to find common elec- 
tricity in circulation, and this was my own opinion when J first noti- 
ced the phenomenon, but the gold leaf electrometer was not in the 
slightest degree affected by the arrangement of fig. 6. It is nothing 
unusual to have shocks following the sudden interruption and renew- 
al of common or voltaic electricity, but, in all such cases, the preex- 
isting forces are powerful and proportionate to the effect. Upon a late 
occasion, while performing the usual galvanic experiments upon an 
executed criminal, | had an excellent opportunity of proving this fact 
in relation to muscular action. The prostrate arm, by the first im- 
pulse, suddenly became elevated, but fell down as rapidly although 
still under the full influence of the uninterrupted current; yet, when, 
by quickly tapping the circuit wire against an extreme plate of the 
battery, a succession of impulses was created, the lifeless arm pre- 
served, vigorously, its upright posture. It is probable, therefore, 
that the nervous fluid, supposing it the same as the voltaic, occasions 
muscular action less by quantity or intensity than by the distinct rep- 
etition of its impulses, the rapidity of which must be inconceiva- 
bly great even during its ordinary action, but infinitely more so when 
it sustains those tremendous convulsive efforts which characterize 
Opisthotonos and other tetanic diseases. Another physiological con- 
clusion suggests itself, as more akin to our subject, and which might 
almost induce one to become a convert to the doctrine of animal 
magnetism. It has been fully proved by Dr. Davy and others, that 
the voltaic current, generated by those animals which possess the 
power of giving shocks, is constantly accompanied by the transverse 
magnetic forces. If, therefore, the nervous power which occasions 
ordinary muscular motion and the different operations of secretion, 
be considered the same as the voltaic, it would follow, that every 
nerve possess a tangential magnetic force; and, further, that, upon 
the supposition that an uniform current proceeds from the brain down 
