The Apache medicine-men are also fully persuaded that crystals possess the virtue of inducing visions, and they have used them for the purpose of finding lost property. To aid in the recovery of stolen ponies is one of the most important tasks of the Apache medicine-man, and to this end his crystal offers great assistance. Capt. John G. Burke relates that he made a great friend of a medicine-man named Na-a-che by giving him a large crystal of denticulated spar, much superior to the crystal he had been in the habit of using for his visions. That this was thoroughly satisfactory to the medicine-man at least, is shown by his statement to Capt. Burke that by looking into his crystal he could see everything he wanted to see. Of the way this came about he did not attempt any explanation.[302] The magic power supposed to dwell within rock-crystal has been recognized in a peculiar way by some natives of New South Wales. They have the barbarous custom of knocking out one or more of the front teeth of their boys at the obligatory initiation ceremonies, and on one occasion Dr. Howitt was entrusted with the care of a number of these teeth, which are believed to preserve a certain undefined connection with the health and fortunes of their former possessors, and on this account great fear was expressed lest the custodian should place the precious teeth in the same bag with some rock-crystals, for the natives thought that the magic power of these crystals would injuriously affect the teeth, and through them the boys, from whose jaws they had been broken.[303] In a paper entitled “The Origin of Jewelry,” read before the British Association, Professor W. Ridgeley says: Australians and tribes of New Guinea use crystals for rain-making, although they cannot bore them, and this stone is a powerful amulet in Uganda when fastened into leather. Sorcerers in Africa carry a small bag of pebbles as an important part of their equipment. So it was in Greece. The crystal was used to light the sacrificial fire and was so employed in the church down to the fifteenth century. Egyptians used it largely under the XII Dynasty, piercing it along its axis after rubbing off the pyramid points of the crystal, sometimes leaving the natural six sides, or else grinding it into a complete cylinder. From this bead came the artificial cylindrical glass beads made later by the Egyptians.