There is another trick very often performed, which, however chemical, is not looked upon in that light, neither do performers attempt to explain it; we mean the exhibition of the Glace Inflammable of the French.
The preparation is made in the following manner: melt some spermaceti over a fire, and add a sufficient quantity of spirit of turpentine, and blend them together. The mixture when cold, will become solid, having somewhat the appearance of ice. If made in hot weather, the vessel containing the melted substances must be immersed in cold water. It does not, we are told, remain in a solid state any length of time.
It floats more or less in the fluid, which of course is the spirit of turpentine. The trick, with this preparation, after having put some of the solid and fluid substance together on a plate, is to pour upon it concentrated nitric acid, or a mixture of eight or ten parts of nitric acid, and two of sulphuric acid; inflammation ensues. It is no other in fact than accension of the oil of turpentine; the addition of the spermaceti is altogether secondary, and its effect, if any, must retard instead of promoting the combustion of the turpentine. The art of making this preparation is in rendering the essential oil solid and transparent, without altering its inflammable properties.
There is another trick performed, by burning a thread, to which an ear-ring is tied, and which, notwithstanding the thread is reduced to a cinder, still holds the ring. This is what the French call the Bague suspendue aux cendres d'un fil. The string is first prepared by soaking it for 24 hours, in a solution of common salt, and drying it; then tying it to a ring, and setting it on fire, avoiding any vibration or oscillation of the string. It is obvious that the salt serves to render the cinder cohesive.
We have an account in Maundrel's Travels from Aleppo to Jerusalem, of the office of the Holy Fire. The ceremony is kept up by the Greeks and Armenians, from a persuasion that every Easter eve, a miraculous flame descends from heaven into the holy sepulchre, and lights all the lamps and candles, as the sacrifice was consumed at the prayers of Elijah.
"On our approaching the holy sepulchre," says Maundrel, "we found it crowded with a numerous and distracted mob, who made a hideous clamour; but with some difficulty pressing through the crowd, we got up in the gallery next to the Latin convent, where we could have a view of all that passed. The people began, by running with all their might, round the holy sepulchre, crying out 'huia,' which signifies, 'This is he,' or, 'This is it.' After this, they began to perform many antic tricks: sometimes they dragged one another along the floor round the sepulchre; sometimes marched round with a man upright upon another's shoulders; at others, took men with their heels upwards, and hurried them about with such indecency, as to expose their nudities; and sometimes they tumbled round the sepulchre like tumblers on a stage. In a word, nothing can be imagined more rude and extravagant than what was acted upon this occasion.
"This frantic humour continued from twelve till four, and then the Greeks first set out in a procession round the sepulchre, followed by the Armenians, and marched three times round it with their standards, streamers, crucifixes, and embroidered habits; and towards the end of the procession, a pidgeon came fluttering into the cupola over the sepulchre, at which the people redoubled their shouts and clamours, when the Latins told the English gentlemen, that this bird was let fly by the Greeks, to deceive the people with a belief that it was a visible descent of the Holy Ghost. The procession being over, the suffragan of the Greek patriarch, and the principal Armenian bishop, approached the door of the sepulchre, cut the string with which it was fastened, and breaking the seal, entered, shutting the door after them, all the candles and lamps within having been before extinguished in the presence of the Turks. As the accomplishment of the miracle drew near, the exclamations were redoubled, and the people pressed with such violence towards the door, that the Turks could not keep them off with the severest blows. This pressing forward was occasioned by the desire to light their candles at the holy flame as soon as it was brought out of the sepulchre. The two miracle-mongers had not been above a minute in the sepulchre, when the glimmering of the holy fire was seen through some chinks in the door, which made the mob as mad as any in bedlam; then presently came out the priests, with blazing torches in their hands, which they held up at the door of the sepulchre, while the people thronged with extraordinary zeal to obtain a part of the first and purest flame, though the Turks laid on with their clubs without mercy. Those who got the fire immediately applied it to their beards, faces, and bosoms, pretending that it would not burn like an earthly flame; but none of them would endure the experiment long enough to make good that pretension. However, so many tapers were presently lighted, that the whole church seemed in a blaze, and this illumination concluded the ceremony."
Maundrel afterwards observes, that the Latins take great pains to expose this ceremony as a shameful imposition, and a scandal to the Christian Religion: but the Greeks and Armenians, lay such stress upon it, that they make the pilgrimages chiefly on this account; and their priests have acted the cheat so long, that they are forced now to stand to it, for fear of endangering the apostacy of the people. They entertain many absurd ideas respecting the miraculous power of the holy fire. Even the melted wax of the candle, which had been lighted by it, is covered over with linen, and designed for winding-sheets; "for they imagine," says Maundrel, "that if they are buried in a shroud, smutted with this celestial fire, it will secure them from the flames of hell!"
Before concluding this article, we shall mention a subject highly interesting in optics, which, in some of its forms, was employed by the old magicians; we mean the phantasmagoria. The exhibitions of this kind, when first got up, drew the attention of Europeans, and particularly the French, who greatly improved the apparatus and machinery, and varied the forms and appearances. The principles of the phantasmagoria are described in every work on Natural Philosophy, which treats of optics. The Dictionnaire de l'Industrie, Encyclopedie Méthodique, Biot's Traité de Physique, in French and in English, the different treatises on philosophy and optics, particularly Dr. Smith's, the Cyclopedias, &c. contain either a description, or the principles of it. The third volume of Biot, especially, is full on the subject of optics. With regard, however, to the narrative and explanation of the appearance of the phantoms, and other figures, a subject which immediately concerns us, the account given by Mr. Nicholson, (Journal of Natural Philosophy, Chymistry, and the Arts, vol. i, p. 147.) is the most interesting. Connected with this optical illusion, is the imitation of lightning and thunder, which, from the account, appears also to have been performed.
The phantasmagoria may be considered nothing more than an application of the magic lantern, the invention of which is attributed to Roger Bacon, who was a contemporary with Vitellio, a native of Poland, who published a treatise on optics, in 1270. John Babtista Porta, of Naples, who discovered the camera obscura, having formed a society of ingenious persons at Naples, which he called the Academy of Secrets, wrote the Magia Naturalis, containing his account of this instrument, and, it is said, the first hint of the magic lantern. Kircher, it is known, received his first information of the magic lantern from this book, and afterwards improved it.
Adams (Lectures on Natural and Experimental Philosophy, vol. ii, p. 232. Appendix by the English editor) very justly observes, that persons, unacquainted with the principles of optics, have been surprised at the great illusion of their sight, by an artificial construction of many optical instruments, exhibited by showmen and others: such, for instance, as the optical and dioptrical paradox; the endless gallery; the animated balls by simple reflection; phantoms; causing the appearance of a flower from its ashes; the optical perspective box, and the cylindrical mirror: to which we may add, the enchanted bottle; the enchanted palace; the magic lantern; the magician's mirror; the perspective mirror; the camera obscura; distorting and oracular mirror; the diagonal opera glass, &c. &c.; all which may be seen in Smith's School of Arts.
We may also remark, that optical exhibitions sometimes accompany those of fire, when performed on a small scale. In the phantasmagoria, for instance, whether before, or at the time the exhibition commences, as well as after, thunder and lightning, if well imitated, produces a good effect.
The mechanism of the phantasmagoria is concealed from the spectators, who have only before their eyes a screen of gauze or gummed muslin