Again, it is stated that the Italian historian, Muratori, makes two references to magic mirrors, one in the possession of Bishop Bartolomeo of Verona, who was murdered by Mastino della Scala in 1338; the other found in the house of Cola di Rienzo (or Rienzi), which had upon its back the word “Fiorone.” Not having been able to verify the statement from literature available in the British Museum, I am in doubt about the last case. It is much more likely that the mirror bore on its back a large flower, than that it bore the word meaning a large flower. Except for obscure references such as these, there is no record of real magic mirrors prior to 1832. Yet a few did undoubtedly exist. There were some in the collection of the royal family of Savoy at Turin, which were later examined by Professor Govi. There was one reputed to be magical in Berlin. The great Von Humboldt thought it worth his while, in 1830, to bring this mirror to Paris to show it to his _confrères_ of the _Académie des Sciences_; but having brought it, found himself unable to show anything. In 1842 several mirrors were brought from Nankin by Admiral Mouchez (commander of “La Favorite”), M. Arosa, and M. Piou. One was in the possession of the Marquis La Grange in 1847. With the opening of Japan to the commercial world, in 1867, came the export of mirrors amongst other articles of metal-work; amongst them some that were of magic quality. One was displayed in 1876 in the Loan Collection of Scientific Apparatus in the western galleries of the South Kensington Museum. The official Catalogue (p. 927) thus describes it: “983 c. Magic Mirror. [Exhibited by] Robert von Tarnow. This mirror is a curiosity, and consists of a brass concave disc with finely polished surface. At the reverse rough side there are several Arabic (_sic_) characters in relief. By exposing the polished surface to the rays of the sun in such a way that they reflect them on the wall, the Arabic figures of the reverse side of the disc become plainly visible in the reflected light on the wall.” It was this mirror which, in the following year, the present writer had in mind when, writing in “Nature,” he proposed that an investigation should be made into the strange optical property so exhibited. Happily at that time his friend Professor W. E. Ayrton was resident in Japan as Professor in the Imperial College of Engineering at Tokio, and he and his colleague, Professor Perry, at once engaged in an exhaustive research on the subject, in the course of which they not only examined some hundreds of mirrors, but also acquainted themselves on the actual spot with the methods of manufacture, which until then were entirely unknown, or misunderstood. A year or two later, after the publication of the researches of Ayrton and Perry, other researches of an entirely confirmatory character were published in France by M. Bertin. In fact, the scientific investigations may be sharply divided into four periods.