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_.