difficulty
proposed by Charles II. In 1679 De Saint Romain, deserting the old
hypothesis of secret 'sympathies,' explained the motion of the rod
(supposing it to move) by the action of _corpuscules_. From this time
the question became the playing ground of the Cartesian and other
philosophers. The struggle was between theories of 'atoms,' magnetism,
'corpuscules,' electric effluvia, and so forth, on one side, and the
immediate action of devils or of conscious imposture, on the other.
The controversy, comparatively simple as long as the rod only
indicated hidden water or minerals, was complicated by the revival of
the savage belief that the wand could 'smell out' moral offences. As
long as the twig turned over material objects, you could imagine
sympathies and 'effluvia' at pleasure. But when the wand twirled over
the scene of a murder, or dragged the expert after the traces of the
culprit, fresh explanations were wanted. Le Brun wrote to Malebranche
on July 8, 1689, to tell him that the wand only turned over what the
holder had the _intention_ of discovering.[186] If he were following a
murderer, the wand good-naturedly refused to distract him by turning
over hidden water. On the other hand, Vallemont says that when a
peasant was using the wand to find water, it turned over a spot in a
wood where a murdered woman was buried, and it conducted the peasant
to the murderer's house. These events seem inconsistent with Le Brun's
theory of _intention_. Malebranche replied, in effect, that he had
only heard of the turning of the wand over water and minerals; that it
then turned (if turn it did) by virtue of some such force as
electricity; that, if such force existed, the wand would turn over
open water. But it does not so turn; and, as physical causes are
constant, it follows that the turning of the rod cannot be the result
of a physical cause. The only other explanation is an intelligent
cause--either the will of an impostor, or the action of a spirit. Good
spirits would not meddle with such matters; therefore either the Devil
or an impostor causes the motion of the rod, if it _does_ move at
all. This logic of Malebranche's is not agreeable to believers in the
twig; but there the controversy stood, till, in 1692, Jacques Aymar, a
peasant of Dauphine, by the use of the twig discovered one of the
Lyons murderers.

Though the story of this singular event is pretty well known, it must
here be briefly repeated. No affair can be be