Towards the end of the ninth century the region about Rome was visited by a dire plague of locusts. A reward was offered for their extermination and the peasants gathered and destroyed them by millions; but all efforts were in vain, since they propagated faster than it was possible to kill them. Finally Pope Stephen VI. prepared great quantities of holy water and had the whole country sprinkled with it, whereupon the locusts immediately disappeared. The formula used in consecrating the water and devoting it to this purpose implies the diabolical character of the vermin against which it was directed: “I adjure thee, creature water, I adjure thee by the living God, by Him, who at the beginning separated thee from the dry land, by the true God, who caused thee to fertilize the garden of Eden and parted thee into four heads, by Him, who at the marriage of Cana changed thee into wine, I adjure thee that thou mayst not suffer any imp or phantom to abide in thy substance, that thou mayst be indued with exorcising power and become a source of salvation, so that when thou art sprinkled on the fruits of the field, on vines, on trees, on human habitations in the city or in the country, on stables, or on flocks, or if any one may touch or taste thee, thou shalt become a remedy and a relief from the wiles of Satan, that through thee plagues and pestilence may be driven away, that through contact with thee weevils and caterpillars, locusts and moles may be dispersed and the maliciousness of all visible and invisible powers hostile to man may be brought to nought.” In the prayers which follow, the water is entreated to “preserve the fruits of the earth from insects, mice, moles, serpents and other foul spirits.” This subject was treated in a lively and entertaining manner by a Jesuit priest, Père Bougeant, in a book entitled _Amusement Philosophique sur le Langage des Bestes_, which was written in the form of a letter addressed to a lady and published at Paris in 1739. In the first place, the author refers to the intelligence shown by animals and refutes the Cartesian theory that they are mere machines or animated automata. This tenet, we may add, was not original with Descartes, but was set forth at length by a Spanish physician, Gomez Pereira, in a bulky Latin volume bearing the queer dedicatory title: “_Antoniana Margarita opus nempe physicis, medicis ac theologis non minus utile quam necessarium_,” and printed in 1554, nearly a century before the publication of Descartes’ _Meditationes de prima philosophia and Principia philosophiae_, which began a new epoch in the history of philosophy.