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. {190} 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 better authenticated, and our version is abridged from the 'Relations' of 'Monsieur le Procureur du Roi, Monsieur l'Abbe de la Garde, Monsieur Panthot, Doyen des Medecins de Lyon, et Monsieur Aubert, Avocat celebre.'