central question remained unanswered-what was the essential difference between the living and the
non-living? The vitalist doctrine of a mysterious, non-corporeal entity was still the best available,
despite increasing evidence against it. Not only were there theoretical objections to electricity being the
"vital force," but also no-one had produced any evidence of a scientific nature to indicate that it played
any role in living things whatsoever.
Fig.1.1. Luigi Galvani, physician, surgeon, anatomist and teacher. As professor of anatomy, Galvani's
lectures were more experimental demonstrations than didactic discussions. A quotation frequently
attributed to him states, "For it is easy in experimentation to be deceived and to think one has seen and
discovered what we desire to see and discover." In addition to being a scientist, Galvani was foremost
a physician, treating rich and poor alike.
The major event was to be provided by a shy, retiring physician and professor of anatomy at
Bologna, Luigi Galvani. Since 1775 he had been interested in the relationship between electricity and
biology and had acquired the apparatus necessary to conduct his experiments. In 1786 quite by
accident, while dissecting the muscles of a frog leg, one of Galvani's assistants happened to touch the
nerve to the muscles with his scalpel while a static electrical machine was operating on a table nearby.
Every time the machine produced a spark the muscle contracted-obviously the electrical force
somehow had gone through the air to the metal in contact with the nerve. But most importantly, the
electricity went down the nerve and produced the muscle contraction. Electricity did have something to
do with how nerves worked! Galvani spent the next five years experimenting on the relationship
between metals in contact with nerves and muscle contraction. We can now speculate that he wished to
avoid the use of the electrical generating machine so that he could produce a muscle contraction by
contact between the nerve and metal only, in order to prove that the nervous principle was electrical.
He must have found that single metals in various circuits did not produce the desired muscular
contraction, and so he then tried using more than one metal in the circuit. He found that if a continuous
circuit was made between the nerve, two dissimilar metals in series, and another portion of the animals
body, muscular contraction would occur. Galvani reported his findings in the Proceedings of the
Bologna Academy of Science in 1791 concluding that the electricity was generated within the animal's
body, the wires only providing the circuit completion. He called this electricity "animal electricity,"
and identified it as the long sought for "vital force". Considering his quiet, unassuming nature, it must
have been with some trepidation that he published such a far-reaching conclusion concerning the most
controversial subject of the time. Nevertheless, he had twelve extra copies printed at his own expense
ELECTROMAGNETISM & LIFE - 11