127. BOLE is an earthy mineral, of yellowish or reddish brown colour, soft, and somewhat unctuous to the touch, and generally found in a massive state.
It exhibits internally a glimmering lustre; and, when put into water, immediately absorbs it, and breaks down into small pieces with a crackling noise. This mineral is farther distinguished by its fracture being conchoidal, or appearing somewhat like the impression of a shell; and by its adhering strongly to the tongue.
Although bole is at present little used except as a basis of tooth powder, and a coarse kind of paint, it was formerly considered an important article in medicine, and used as an astringent. We are informed that tobacco pipes are sometimes made of this mineral; and that it is employed as an ingredient in the glaze of some kinds of earthen ware.
It is chiefly imported from the Levant; though it has also been found in considerable beds in Silesia and Saxony.
128. LEMNIAN EARTH is a kind of bole of yellowish grey, or yellowish white colour, sometimes marbled with rust-like spots.
It is distinguished from bole by being dry and not unctuous to the touch, dull internally, adhering slightly to the tongue, and its fracture being earthy.
With the ancients this mineral was considered an almost invaluable medicine. They procured it chiefly from Armenia, and the island of Lemnos, in the Grecian Archipelago. The Lemnian bole was held so sacred that it was dug in the presence of the priests of Venus, and, after having been mixed by them with goat’s blood, was moulded into cakes, which were impressed with the figure of a goat, to authenticate them. This done, it was administered as a consecrated remedy; and, even so lately as the sixteenth century, the vein of bole in Lemnos was annually opened on the sixth of August, and, after certain prayers by the priests, so much of the earth was taken out as was thought sufficient for the consumption of the ensuing year. The entrance was then closed, and the severest punishments were denounced against any one who should open it without permission. A portion of the earth was sent to Constantinople, where it was made into small cakes, and sealed by the ministers of the Emperor; the remainder was prepared in the island, and was impressed with the seal of the Governor. Not many years ago, it was customary with certain empirics on the Continent, to sell this substance in sealed packets, as a nostrum of great value, and particularly as possessing astringent properties of very extraordinary nature.
129. FULLER’s EARTH is a well-known mineral, generally of greenish colour, more or less mixed with brown, grey, or yellow: of soft and almost friable texture, and somewhat unctuous to the touch.
When put into water it immediately absorbs it, and breaks down into a fine pulp.
This earth is valuable for its property of taking grease out of woollen and other cloths, which, on a large scale, is effected by the operation called fulling, whence its name has been derived. This operation, which is performed by a kind of water mill, called a fulling mill, is particularly necessary with respect to new cloths, to extract from them the grease and oil that have been used in their preparation.