Popular Science Monthly/Volume 24/December 1883/The Natural Setting of Crystals
THE study of natural history has of late years been largely directed to the observation of laws according to which the development of the individual species and genus takes place. Although the vital principle which determines the growth and the nature of the animal or plant eludes the search of shrewd and practiced observers, yet the modes in which that principle manifests itself are in many cases pretty well understood. In numberless instances we have been shown the purpose with which Nature works on unceasingly toward certain definite anticipated ends. It is this fixed intent of Nature, rationally and hopefully pursued, which reveals the thought of the universe. The processes of growth and of change are evident enough to be familiar, but it is the reason for these phenomena which so often makes them miracles of wonder to the observer. Care, intelligence and skill will everywhere be seen, but there is a marked distinction between the growth that goes on under the supervision of an intelligence wholly-external to the form which is brought into being, as in the case of a crystal, and that development which is made according to instinctive or conscious tendencies implanted in the germ.
Tree, shrub and grass show evidence of effort on the part of the individual directed to quite obvious ends. The form assumed is in every instance such as to enable the plant to resist the violence to which it may be exposed. All the energies controlled by vital force are directed to supplying wants felt or anticipated. The tree in its growth develops strength where strength is needed, just as man by exercise increases his muscular power. In the formation of crystals another law predominates. It matters not whether these are safely hidden away in the caverns of the earth, or are exposed to risk of destruction upon its surface. They usually occur attached to one another, or to the faces of the rock. In the latter case, such as have unequal axes will be found so placed as to have their longest axes at right angles to the surface to which they are attached, or, if the surface be curved, this axis will be at right angles to the plane tangent to the curve at that point. This arrangement will be seen most plainly upon examination of a geode lined with quartz-crystals. It provides for the setting of the largest number of crystals upon a given surface, but puts them in the position of the least stable equilibrium quite unlike the sturdy posture assumed by a tree deeply rooted to the soil, and having its fibers most strongly interlaced in the region of its base. This setting of crystals displays them to the best advantage, but it leaves them more exposed to abrasion than would any other position, and more likely to be removed from their place. No provision has been made to guard against external violence, and in this may be found a striking point of distinction between an animate and an inanimate entity.