When you present yourself before a company, in order to perform this experiment, you are to carry the tube in your pocket, and holding the phial in your hand, you are to say, “Ladies and gentlemen, here is a phial containing liquid blood; I hope to make you know by it the person most addicted to love in the company. “Please to observe that I pour a little of this liquor in this tube. As you might imagine that this liquor, like that put in thermometers, may rise by dilating itself when exposed to heat, and consequently the pressure of the hand will suffice to produce this effect, and it will condense by rarifying when exposed to cold; I assure you, ladies and gentlemen, it is not the case; this liquor differs entirely from that put in thermometers; and you may easily be convinced of it before I make the experiment I promised you. You may put it near the heat of a candle, and even that of a fire, without any degree of heat making it rise in the least; but by a peculiar and sympathetic virtue you will see it boil, when the tube is touched by a person of an amorous disposition.” Then take out of your pocket a little potash, keep it in the interior part of the hand that holds the tube at the top, as if you wanted to keep it shut, and as soon as the person you wish to make pass for the most amorous in the company takes the lowest part of the tube in his hand, you are to let fall dexterously a little of the potash in it, and you will see the liquor boil and rise to the top of the tube, to the great astonishment of the spectators. CHAP. XXIII. _To extinguish a wax Candle at eighty or a hundred Paces distance, by firing a Gun loaded with Ball, and to be certain of not missing, however unskilful may be the Marksman._ This experiment may be easily tried in the country, and even in town, in a garden that is rather large: the best marksman may be challenged, and undoubtedly worsted. Load a gun with a common charge of powder, and a leaden ball. Your opponent will do the same on his side; then let him fire first, that you may see him miss his aim, as it is very difficult at such a distance to put out a candle. After having rallied him on his pretended skill, you will fire in your turn, and will extinguish the candle, to the great astonishment of the spectators, who saw you load your gun in the common way with powder and ball, but did not perceive that your ball was pierced through and through in the form of a cross, as is represented by the figure that follows: [Illustration] The whole magic of this experiment consists in this pierced ball, by which the elasticity of the air that drives it acquires a divergent force, by passing through the holes of the ball, and produces this surprising effect. CHAP. XXIV. _To cut a Glass, a Looking-glass, or even a Piece of Crystal, let it be ever so thick, without the Help of a Diamond, in the same Shape as the Mark of the Drawing made on it with Ink._