From Purcell's Electricity and Magnetism

A spectacular conclusion of one of the popular exhibitions of the time was likely to be the electrification of a boy suspended by many silk threads from the rafters; his hair stood on end and sparks could be drawn from the tip of his nose.

(pp 88 of second edition)

It sounds as if this wasn't something that hurt the boy in the act, but if there are sparks, there must be significant current running through his body, right? Were the sparks simply too small to cause serious damage, or is there a reason that drawing sparks from the boy doesn't affect his physiology?

  • $\begingroup$ Were they drawing sparks continuously? If not, it's only a static shock. I used to wear socks, shuffle around the house, and touch my sister to give her a shock. Harmless. Hurts, though. And a pretty high voltage. But it's only fleeting, so it's harmless. $\endgroup$ Commented Mar 1, 2012 at 1:40
  • $\begingroup$ By continuously I mean completely continuously. A spark every second is fine, but it would hurt depending on the magnitude. $\endgroup$ Commented Mar 1, 2012 at 5:23
  • $\begingroup$ It is the power behind it, it is high voltage built up but little power.the first generators were triboelectric en.wikipedia.org/wiki/Electrostatic_generator, high voltages small currents. $\endgroup$
    – anna v
    Commented Mar 1, 2012 at 7:36

1 Answer 1


What is required for sparks across a gap is a high voltage, while what determines whether something will do you harm is the amount of current. You can theoretically survive almost any voltage so long as the current is sufficiently low. It's just that most sources of electricity that have high voltages tend also to have high current.


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