Primitive Man

by Louis Figuier

We must also add that it is not probable that all caverns originated in the same way; but that one or other of the several causes just enumerated must have contributed to their formation.

Under the general denomination of caverns, all kinds of subterranean cavities are comprehended; but it will be as well to introduce several distinctions in this respect. There are, in the first place, simple clefts or crevices, which are only narrow pits deviating but slightly from the vertical. Next we have grottos (or baumes as they are called in the south of France), which generally have a widely opening inlet, and are but of small extent. Lastly, we must draw a distinction between these and the real bone caverns, which consist of a series of chambers, separated by extremely narrow passages, and are often of very considerable dimensions. Some of these caverns occupy an extent of several leagues underground, with variations of level which render their exploration very difficult. They are generally very inaccessible, and it is almost always necessary to ply the pick-axe in order to clear a way from one chamber to another.

In most of these grottos and caverns the ground and sides are covered with calcareous deposits, known by the name of stalactite and stalagmite, which sometimes meet one another, forming columns and pillars which confer on some of these subterranean halls an elegance replete with a kind of mysterious charm.

These deposits are caused by the infiltrated water charged with carbonate of lime, which, oozing drop by drop through the interstices of the rock, slowly discharge the carbonic acid which held the carbonate of lime in solution, and the salts gradually precipitating form the crystalline or amorphous deposits which constitute these natural columns.

The calcareous deposits which spread over the ground of the caverns are called stalagmite, and the name of stalactite is given to those which hang down from the roof, forming pendants, natural decorations, and ornaments as of alabaster or marble, producing sometimes the most magnificent effects.

Under the stalagmite the largest number of animal bones have been found. This crust, which has been to them a preservatory grave, is so thick and hard that a pick-axe is required in order to break it. Thanks to the protecting cover, the bones have been sheltered from all the various causes of decomposition and destruction. The limestone formed a kind of cement which, uniting clay, mud, sand, flints, bones of men and animals, weapons and utensils into a compact mass, has preserved them for the study and consideration of scientific men in our own days.

The soil called bone-earth is, in fact, found under the crystalline bed which covers the ground of the caverns.

Fig. 21, which represents a section of the cave of Galeinreuth, in Bavaria, will enable us clearly to understand the position occupied by the bones in most of these caverns.