It is almost needless to speak of the ex tent to which inorganic bodies differ from or ganic in these respects ; they are rigid and hard in all their parts alike, and never vary in consistence from the moment of their forma tion to that of their disintegration or decom position.
The elementary particles or molecules en tering into the composition of organized and unorganized objects, also differ in their essen tial nature. All organized beings, in fact, whether their solids or fluids are regarded, appear to be made up of or to contain glo bular or oval and sometimes flattened cor puscles. The simplest plants,—the confervw, tremellm, &c., and the simplest animals,—the infusoria, polypi, &c., are alike composed of globules and a fluid ; nor is the case different as regards the most complicated vegetable or animal that exists. The elementary globule has now been discovered in almost all the solids and fluids both of vegetable and of animal bodies,—in the sap and cambium or succus proprius of vegetables, and in the blood, chyle, milk, and other fluids of animals ; in the fecula, albumen, parenchyma of the leaves, cells of the flowers, &c. of plants, and in the cellular membrane, muscle, brain, nerve, gland, &c. of animals.
Nothing of the same kind has yet been de tected among inorganic bodies. Angular par ticles separable to infinity into others of a like description are the elements of composition in minerals.
Globules, then, are to be regarded as the elementary constituents of organized bodies, as the ultimate molecules possessing a distinct form, which by their aggregation compose them. The first step, indeed, in the singular pro cess by which infusory animals are eliminated during the decomposition of organized sub stances, is the formation of globular corpuscles; these, by their subsequent aggregation in some cases and individual evolution in others, appear to give birth to the organized atoms that by-and-by make their appearance ; and, as we have said, globules are now admitted to form the basis of the different tissues which enter into the composition of the very highest among animals. These various tissues, in fact, would seem to result from the different modes in which the elementary globules are disposed ; and it is not improbable that the difference of function they exhibit may yet be found harmony with, and perhaps depending on, pe culiarity of arrangement in their constituent molecules.
This aggregation of the organic molecules into a variety of tissues and peculiar organs forms another essential feature of difference between the organized and the unorganized world. Minerals, indeed, as they manifest no variety of phenomena analogous to those of life, required no diversity of elementary con stitution in their different parts ; they are con sequently homogeneous. In minerals the com
ponent molecules are arranged in layers placed one upon another, so that their crystals can be readily cleft in a variety of directions, according to the elementary arrangement of these. In vegetables and animals, on the other hand, the constituent molecules always form tissues, the fibres of which interlace or cross one another ; in no living or organic thing do we observe aught similar to what is called the cleavage in minerals.
From this it comes that minerals are as com plete in their parts as they are in their masses : the minutest spark of carbonate of lime has all the properties of a crystal of this substance, were it as large as a mountain. The case is very different in regard to organized beings ; these consist of a number of organs, the sum of whose actions constitutes the peculiar vitality of each being, and no individual part or organ enjoys capacity to manifest itself abstractedly from the system to which it belongs. All the parts of organized bodies are mutually en chained by bonds of the strictest causality ; this even follows necessarily from the manner in which they originate and are evolved. The radicle that bursts from the fecundated seed of a plant determines the growth of the stem, which subsequently and in its turn plays the same part with reference to the leaves and flowers,—the parts that appear first are the cause of the appearance of those that follow at later stages. No relation of this kind exists among inorganic bodies. When a crystal is formed in the midst of a fluid, the particles composing it unite, in conformity with the mere laws of cohesion and affinity, not in consequence of any determining influence in the particles which cohered the first,—each stage or period of the process of crystallization is independent of that which preceded it. Whilst the parts of an inorganic body, therefore, can exist with all their qualities, as well in a state of disin tegration as in one of aggregation, the com ponent parts of organic bodies can only exist with their distinguishing properties when united to the entire being. Individuality in the or panic world, far from existing in the integral molecule as it does in the inorganic, can only be said to exist in the mass of integral mo lecules united into that congeries of organs which constitutes a particular being. As a consequence of this independence on the one hand, and dependence on the other, we find, that whilst in the inorganic world the several parts may be modified without the others feeling the influence of the change in duced, in the organic, implication of one part and modification of one action are commu nicated to and manifested in the state and actions of all the other parts.