Further thoughts on A.C. vs. D.C. from C.D. Prewitt
MOTHER NO. 20 contained some feedback on my statements in
NO. 19 about the advantages of direct over alternating
current, and I'd like to offer a rebuttal that's based on
my own experience . . . not on theory, as the criticisms
seem to be.
RELATED CONTENT
First of all, an alleged danger of D.C. is that one might
not be able to let go of the electrodes that are producing
the shock. Now, I've been hearing that statement all my
life, and I'm convinced that it's nothing but theory, with
no real foundation. I've had all sorts of shocks—up
to and including one of 10,000 volts, when one contact was
with my left had and the other with both feet thoroughly
grounded—and I've never felt any inclination to hold
on. On the contrary, either kind of current causes an
irresistible urge to disengage, which some people feel so
strongly that they claim the jolt has "knocked me down".
I've seen victims do some wild jumping, but I've never seen
one want to continue grasping the conductor.
In fact, I wonder whether shocks are necessarily as deadly
as is generally believed. That time I was hit with 10,000
volts (A.C.) I didn't dare pick up a cup of coffee for
three days afterward because I was sure I'd slosh it all
over the room. I was convinced that my nervous system had
had it . . . yet a week later I was as good as new. If some
people's notions are true, my heart must have moved out of
the way.
Yes, I admit that even a small current could kill you if it
passed through the heart . . . but to accomplish that you'd
probably have to introduce electrodes into the organ.
Actually, of course, a current (unless it's of very high
frequency) doesn't flow through one geometric line, but
through a considerable area. In a case like my accident,
one's heart might or might not get a lethal amount.
By the way, Peter Grant's statement that the body's
resistance is only 500 ohms is clearly out of line . . .
it's known that across any substantial part of the
anatomy—as from hand to hand—the figure is well
up in the thousands of ohms. Since I had no exact data of
my own on this point, I made a test by thoroughly wetting
my hands and grasping the prods of an ohmmeter. I got a
reading of 50,000 ! I then attached the prods to
sizable pieces of metal (something no one would do where
there was shock hazard). When I again wet my hands and
gripped these conductors, I couldn't get the indicator
below 20,000 ohms.
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