Tales of Space and Time

So far, at least, Mr. Wace was able to verify the remarkable story of Mr. Cave. He has himself repeatedly held this crystal in a ray of light (which had to be of a less diameter than one millimetre). And in a perfect darkness, such as could be produced by velvet wrapping, the crystal did undoubtedly appear very faintly phosphorescent. It would seem, however, that the luminousness was of some exceptional sort, and not equally visible to all eyes; for Mr. Harbinger--whose name will be familiar to the scientific reader in connection with the Pasteur Institute--was quite unable to see any light whatever. And Mr. Wace's own capacity for its appreciation was out o