The perpendicular fissures and joints of quarries are often filled and incrusted with concretions, which are sometimes as transparent as crystal, of a regular figure, sometimes opaque: the water flows through the perpendicular clefts, and penetrates even the compact texture of the stone; the stones which are porous, imbibe so great a quantity of water, that the frost splits and divides them. The rain by filtrating through the beds of marle, stone, and marble, load themselves with every matter they can take up or dissolve. These waters at first run along the perpendicular clefts, afterwards penetrate the beds of stone, and deposit between the horizontal joints, as well as in the perpendicular clefts, the matters they have brought with them, and form these different congelations according to the nature of the matters they have deposited; for example, when the water filters through marle, chalk, or soft stone, the matters which they deposit are a very pure and fine marle, which generally enters in the perpendicular cleft of the rocks under the form of a porous, soft substance, commonly very white and light, which naturalists have called _Lac lunac_, or _Medulla Saxi_. When these streams of water, loaded with lapidific matter, flow through the horizontal joints of soft stone or chalk, this matter attaches itself to the surface of the blocks of stone, and forms white, scaly, light, and spongy crust; which some authors have named _Mineral Agaric_, from its resemblance to Vegetable Agaric: but if the strata are of common hard stone, proper to make good lime, the filter being then more close, the water will issue from it loaded with lapidific matter, more pure and homogeneous, and whose molecules uniting more intimately, will form nearly concretions of the hardness of stone, with a little transparency, and we shall find on the surfaces of the blocks in these quarries, stony incrustations variously disposed, which entirely fill up the horizontal joints. In grottos and cavities of rocks, which may be looked upon as the basons of perpendicular clefts, the diverted direction of the streams of water, give different forms to the concretion which result therefrom. They in general have the appearance of a cone attached to the top of the vault, although they may more properly be considered as hollow and white cylinders, formed by a concentrical surface; these congelations sometimes descend, by drops, to the bottom, and form pillars, and a thousand other figures, as uncouth and ridiculous as the names which naturalists have been pleased to give them, such as, _Stalactites_, _Stelegmites_, _Osleocollae_, &c.