19 2 V LIMESTONE FAMILY. into yellowish-white, and greyish-white. These are the colours it exhibits when dry: when moist, and in its ori ginal repository, its colours are pale blackish-brown or brownish-black, also dark yellowish, hair, and wood brown ; seldomer dark ash-grey, smoke-grey, or green ish-grey ; more rarely of a colour intermediate between hair or liver brown and yellowish-grey, which passes into muddy cream-yellow. It consists of fine sandy or dusty particles, which are loosely cohering. It is dull or feebly glimmering. The dusty particles feel very fine, and soft. It soils strongly. "When it is rather compact, it becomes shining in the streak. It emits a strong urinous smell. Chemical Characters. It effervesces strongly with acids. Constituent Parts. It is said to be composed of Lime, Alumina, Silica/ and Bitumen.—I'riesleben. Geognostic and Geographic Situations. It occurs in beds in the first and second flcetz limestone and gypsum formations, along with stinkstone, in Thu ringia and Mansfeld. Observations. 1. It passes into Limestone, Stinkstone, and Black Clay. 2. It is sometimes mixed with mica and calcareous- spar, also with iron-ochre, and seldomer with pure clay, quartz, sand, gypsum, and aphrite. 3. Masse*-