It is possible to allege against my reasoning the secrets of physics and chemistry, which produce an infinity of wonderful effects, and appear beyond the power of natural agency. We have the composition of a phosphorus, with which they write; the characters do not appear by daylight, but in the dark we see them shine; with this phosphorus, figures can be traced which would surprise and even alarm during the night, as has been done more than once, apparently to cause maliciously useless fright. _La poudre ardente_ is another phosphorus, which, provided it is exposed to the air, sheds a light both by night and by day. How many people have been frightened by those little worms which are found in certain kinds of rotten wood, and which give a brilliant flame by night. We have the daily experience of an infinite number of things, all of them natural, which appear above the ordinary course of nature,[438] but which have nothing miraculous in them, and ought not to be attributed to angels or demons; for instance, teeth and noses taken from other persons, and applied to those who have lost similar parts; of this we find many instances in authors. These teeth and noses fall off directly when the person from whom they were taken dies, however great the distance between these two persons may be. The presentiments experienced by certain persons of what happens to their relations and friends, and even of their own death, are not at all miraculous. There are many instances of persons who are in the habit of feeling these presentiments, and who in the night, even when asleep, will say that such a thing has happened, or is about to happen; that such messengers are coming, and will announce to them such and such things. There are dogs that have the sense of smelling so keen that they scent from a good distance the approach of any person who has done them good or harm. This has been proved many times, and can only proceed from the diversity of organs in those animals, some of which have the scent much keener than others, and upon which the spirits which exhale from other bodies act more quickly and at a greater distance than in others. Certain persons have such an acute sense of hearing that they can hear what is whispered even in another chamber, of which the door is well closed. They cite as an example of this, a certain Marie Bucaille, to whom it was thought that her guardian angel discovered what was said at a great distance from her. Others have the smell so keen that they distinguish by the odor all the men and animals they have ever seen, and scent their approach a long way off. Blind persons pretty often possess this faculty, as well as that of discerning the color of different stuffs by the touch, from horse-hair to playing-cards.