in natural history, the matter which runs down in burning torrents from the craters of volcanos, and which probably contains mineral and metallic particles, it being ponderous and hard.

Some of the sciari are coarse, and others fine and polished on the surface; some of them are black, others grey, others reddish, and others of the colour of iron, and many of them have coverings of pure sulphur over their whole surface. They seem to be the result of many sorts of minerals melted together.