neys, muscles, ligaments, tendons, cartilages, membranes, bones, &c.; all of which are generated from the albuminous, fibrinous, oily, and saline constituents of the blood; which is formed by the immediate union of oxygen, hydrogen, carbon, and nitrogen, into quaternary combinations. Most of the fluids secreted by animals, such as gastric juice, bile, mucus, pancreatic and seminal liquor, are also quaternary compounds. But they also secrete several combinations that are ternary, as the sugar of milk and urine, fat, resin, and the volatile oily matters termed civit and castor. On the other hand, there are many plants that contain nitrogen, which is abundant in mushrooms, and has been recently discovered in the vegetable salifiable bases, as morphine, narcotine, veratrine, solanine, delphine, emetine, quinine, cinchonine, pollenine, and some other like compounds. From which it is obvious, that the more complicated organization of animals than of plants, is not owing merely to the greater complexity of their elementary composition, as will further appear hereafter. Yet there cannot be a doubt, that the structure and functions of all organized bodies are determined by the chemical constitution and fundamental properties of their ultimate elements, which are modified by every increase or diminution in the quantity of caloric around their atoms.

CAUSE OF VITAL AFFINITY.

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Now the great question that lies at the very foundation of organic chemistry is, whether the power of forming ternary and quaternary compounds, with the aptitude for renewing their composition by assimilation and elimination, be owing to the same cause which governs the affinities of dead matter, or to some peculiar principle of a totally distinct nature, as maintained by Berzelius, Tiedmann, Müller, and nearly all the most distinguished physiologists of the present day? Nothing but an earnest appeal to nature, and a careful examination of facts can resolve this difficult problem.

The learned Tiedmann observes very justly, that the difficulty of explaining the phenomena of life by the laws of physics, may be owing to our imperfect knowledge of natural phenomena in general. But Müller contends, that" the power by which the elements of organized bodies are united into ternary and quaternary compounds in opposition to the laws of chemistry, is, without doubt, a peculiar force, or imponderable matter, unknown in inorganic nature." Yet he admits in another place, that the cause of crystallization is not more profoundly hidden than that of organization. (Elements of Physiology, pp. 22, 251.) That the power of oxygen, hydrogen, carbon, and nitrogen, to form the proximate constituents of living bodies, is owing to the fundamental properties of these elements,

would appear from the fact, that no others are capable of entering into ternary and quaternary compositions; in short, that no plant or animal was ever formed or nourished by any other elements. And that the tendency of dead organized bodies to undergo decomposition, is owing to the same active principle that enables these elements to form ternary and quaternary combinations, is proved by the circumstance that this tendency is augmented by every addition of caloric, which I have shewn to be not only the universal bond, but the great decomposer of all matter.

During the decomposition of organized bodies under the influence of a summer temperature, a portion of their substance enters into binary compounds of water, carbonic acid, and ammonia. But during this process, another portion of the same elements unites to form the simplest species of microscopic plants and animalcules, without the concurrence of parents, seeds, eggs, or the addition of any other principle than was concerned in the generation of water, carbonic acid, &c. And as it has been shewn that the form of crystals depends on the nature of their atoms, modified by the temperature at which they are aggregated, so has it been observed that the specific character of infusoria, generated during the fermentation of albumin, fibrin, starch, gluten, and other organic compounds, varies ac

ANIMALCULES AND ENTOZOA.

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cording to the different species of matter employed. Those simple organizations termed entozoa, generated in the parenchymatous substance of many animals, without the visible existence of any parents, eggs, or germs, also vary according to the nature of the animal, and even of the organ in which they are formed.* Nor is there anything more mysterious in this, than in the ordinary process of generation, only that we are more accustomed to the latter; or that specific contagions should be generated by certain combinations of filth, and vitiated animal secretions, as in gonorrhea, lues venerea, small pox, the itch, &c., that have the power of propagating themselves in a mode analogous to the production of fermentation by yeast; which,

It is said that twelve different species of entozoa have been found in man, six in the alimentary canal and its appendages, one in the lungs, one in the brain, one in the eyes, one in the muscles, one in the kidneys, one in the ovaries, and one in the skin: while in the several organs of the sheep, nine species have been discovered; eleven in the ox; nine in the horse, hog, and fox; and eight in the hare. They have been found in birds, reptiles, fishes, crustacea, and mollusca. (See Fletcher's Rudiments of Physiology, part ii. p. 12.)

They have also been found in the embryons of these animals; from which it is maintained by Pallas, Müller, Werner, Bloch, Goeze, Braun, G. R. Treviranus, Rudolphi, and others, that they are the products of non-assimilated matters, or morbid productions formed in the humours or parenchyma of the organs, in a mode resembling the generation of infusoria during the fermentation of organic matter. (Tiedmann's Comp. Physiology, p. 40.)

according to the observations of De la Tour, is composed chiefly of organic molecules that have the faculty of multiplying themselves in all fermentable matters.

Should it be objected that such molecules, like the different species of moulds, confervæ, and animalcules, can be generated only from matter that has been once organized, I answer that the elements of oxygen, hydrogen, carbon, and nitrogen, wherever they exist, are capable of entering into the universal tide of life; whether locked up with rocks, metals, and beds of coal, in the bowels of the earth, or floating over its surface in the state of air and water. When once formed, the germs of plants have the power of converting the binary combinations of water and carbonic acid into ternary compositions of lignin, sugar, starch, and other organic products, which are thus prepared for entering into the composition of more exalted species of organization-while it is certain, that whatever the cause of vital action may be, it is incapable of converting the elements of mineral bodies into the sap, cambium, and solid structure of plants; or into chyme, chyle, blood, and the different organs of animals. Owing to the comparative inertness of their elements, mineral bodies have the power of entering into binary combinations only, which maintain their original state of aggregation until destroyed by chemical agency, and