In planning to build a temple of fine marbles Solomon found embarrassing the prohibition in the Mosaic law forbidding one to cut stones for the altar of the Lord with iron. But then he sought by an experiment in worms what the art of man knew not. He shut up the fledglings of an ostrich in a glass vase, so that the mother bird could see them but could not get at them to feed them. The ostrich thereupon flew (?) off to the desert and came back with a worm. It then broke the glass vase by smearing it with the blood of this worm. Solomon found this worm, called Thamur or the worm of Solomon, equally efficacious in cutting marble.
Trees.
In speaking of trees most manuscripts[1294] tell of an oak under which Abraham dwelt and which lasted until Constantine’s time. The trees in the Garden of Eden or terrestrial paradise are also discussed, though of course no longer accessible. Josephus is cited concerning trees near the Red Sea and apples of Sodom. Thomas thinks that the Sun-tree and Moon-tree mentioned in Alexander’s letter to Aristotle had been referred to much earlier in the benediction of Joseph in Deuteronomy. As for the responses which these trees are said to have given Alexander, Thomas has little doubt that this was the work of demons, although some contend that it was done by divine permission through ministering angels.
Marvelous virtues of stones.
Like Marbod, Thomas points out that, while plants and fruits receive their virtues “through the medium of the operations of nature,” no excess of cold or heat can be observed in stones to account for their miraculous powers, such as conferring invisibility, and that consequently their virtues must come direct from God. He alludes to the belief that Solomon imprisoned demons beneath the gems in rings, and cites the fifteenth book of The City of God for the statement that demons are attracted by various stones, herbs, woods, animals, and incantations.
An adamantine mariner’s compass.
While Thomas’s exposition of the virtues of gems is largely based upon Marbod, in discussing adamas or adamant he introduces a description of the mariner’s compass, concerning which Marbod is silent and which had probably not been invented or introduced in western Europe that early, although Neckam of course alludes to it before Thomas. After speaking of a variety of adamant which can be broken without resort to goat’s blood but which will attract iron even away from the magnet, Thomas adds that it also betrays the location of the star of the sea which is called Maria. When sailors cannot direct their course to port amid obscure mists, they take a needle and, after rubbing its point on adamant, fasten it transversely on a small stick or straw and place it in a vessel full of water. Then by carrying some adamant around the vessel they start the needle rotating. Then the stone is suddenly withdrawn and presently the point of the needle comes to rest pointing towards the star in question.[1295]
The mariner’s compass and magic.
Having concluded this description of a mariner’s compass, Thomas again follows the poem of Marbod and goes on to say that the adamant is also said to be potent in magic arts, to make its bearer brave against the enemy, to repel vain dreams and poison, and to benefit lunatics and demoniacs. I mention this accidental juxtaposition of the mariner’s compass and magic because, as we shall find in the case of Roger Bacon, it has often been stated that those in possession of the secret of the mariner’s compass were long afraid to reveal it for fear of being suspected of magic, or that sailors were at first afraid to employ the new device for the same reason. This passage in the De natura rerum is as far as I know the only one in the sources that might even seem to suggest such a connection, but Thomas does not really connect the compass and magic at all. Later in the same book, in discussing the magnet, he says nothing of the compass, although repeating the usual statements that the magnet attracts iron, is used in magic, and has the occult property of revealing an unchaste wife.
Occult virtues of sculptured gems.