MILL-STONE, the stone by which corn is ground. The mill-stones which we find preserved from ancient times are all small, and very different from those in use at present. Thorpeby mentions two or three such found in England, among other Roman antiquities, which were but 20 inches broad; and there is great reason to believe that the Romans, as well as the Egyptians of old, and the ancient Jews, did not employ horses, or wind, or water, as we do, to turn their mills, but made their slaves and captives of war do this laborious work; they were in this service placed behind these mill-stones, and pushed them on with all their force. Sampson, when a prisoner to the Philistines, was treated no better, but was condemned to the mill-stone in his prison. The runner or loose mill-stone, in this sort of grinding, was usually very heavy for its size, being as thick as broad. This is the mill-stone which is expressly prohibited in scripture to take in pledge, as lying loose it was more easily removed. The Talmudists have a story, that the Chaldeans made the young men of the captivity carry mill-stones with them to Babylon, where there seems to have been a scarcity at that time; and hence, probably, their paraphrase renders the text "have borne the mills, or mill-stones;" which might thus be true in a literal sense. They have also a proverbial expression of a man with a mill-stone about his neck; which they use to express a man under the severest weight of affliction. This also plainly refers to this small sort of stones.
Rhenish Mill-Stone, is classed by Cronstedt among the volcanic products, on account of its appearance, which is a blackish grey, porous, and perfectly resembling a lava of Mount Vesuvius.