Eber and Meyer pretended that these red particles were infusory animals. On this important and curious subject I shall quote Muller’s opinion: “The question whether the blood be living fluid or not, calls to mind a critical state of our science. Every thing which evidences an action which cannot be explained by the laws of inorganic matter, is said to have an organic, or, what is the same thing, a vital property. To regard merely the solids of the body as living, is incorrect, for there are strictly no organic solids; in nearly all, water constitutes four-fifths of their weight. Although, then, organic matter generally be considered as merely ‘susceptible of life,’ and the organized parts as ‘living,’ yet the blood also must be regarded as endowed with life, for its action cannot be comprehended from chemical and physical laws. The semen is not merely a stimulus for the fructification of the egg, for it impregnates the eggs of the Batrachia and fishes out of the body; and the form, endowments, and even tendencies to disease, of the father, are transferred to the new individual. The semen, therefore, although a fluid, is evidently endowed with life, and is capable of imparting life to matter. The impregnable part of the egg, the germinal membrane, is a completely unorganized aggregation of animal matter; but, nevertheless, is animated with the whole organizing power of the future being, and is capable of imparting life to a new matter, although soft, and nearly allied to a fluid. The blood also evidences organic properties; it is attracted by living organs, which are acted upon by vital stimuli. There subsists between the blood and the organized parts a reciprocal vital action, in which the blood has as large a share as the organs in which it circulates.”
This doctrine is, no doubt, ingenious, but I do not consider it as conclusive. It is not because that in inflammation, the blood becoming solid, forming pseudo membranes, which are shortly after supplied with a proportion of blood-vessels, blood possesses life. If this adventitious coagulation were not supplied with blood, it would prove a foreign body; but it is not, therefore, shown that the circumstance of its possessing vitality after its formation is a proof of the life of the blood; it only shows that the secretions of the blood are endowed with a susceptibility of life, when having assumed a solid form, needing vessels for its support. I shall not dwell longer on a professional question of great interest, but which would need a development foreign to the nature of these sketches.
The Greeks had distinct appellations for the cause and result of life; the former they termed ψυχὴ the latter ζωὴ. The essential nature of life is, and most probably will ever remain, an impenetrable mystery. Living matter is endowed with a property which we call life; but to find out to what we may venture to attribute this property, is a vain and hypothetical attempt. Equally vain and absurd have been the endeavours to ascertain whether life began at the creation to be subsequently transmitted from parent to offspring, or owed its origin to a spontaneous generation from matter. Many ancient philosophers considered matter as eternal: such was the doctrine of the Pythagoreans; amongst whom we must particularly notice Lucanus Ocellus, whose system, developed in a work written in the Attic dialect, was adopted by Aristotle, Plato, and Philo-Judæus. This work was first translated into Latin by Nogarola. These doctrines led to the unanswerable question, What was this matter—this invisa materia—from which every thing visible has proceeded? Has it existed from all eternity, or has it been called into being by the Creator? Has it uniformly exhibited its present harmonious arrangement, or was it once a waste and shapeless chaos? Was this matter endowed with intelligence as a whole, or in its separate fractions?
The eternity of matter was maintained by these philosophers from the belief that no thing could be created out of nothing, and that no thing could ever return to nonentity. Such was the doctrine of the Epicureans, of Democritus, and of Aristotle. The poets were of the same belief; and Lucretius expresses himself as follows:
Ubi viderimus nihil posse creari
De nihilo, tune, quod sequimur, jam rectiùs inde
Perspiciemus.
Persius maintains the same idea:
Gigni
De nihilo nil, in nihilum nil posse reverti.
This dogma was no doubt transmitted to the Greeks from the East; and, to the present day, it is a doctrine of the Brahminical creed, clearly expressed in the following terms in their Yajur Veid: “The ignorant assert that the universe in the beginning did not exist in its author, and that it was created out of nothing. O ye, whose hearts are pure! how could something arise out of nothing?” The fathers of the church embraced a similar belief; and Justin Martin says that “the word of God formed the world out of unfashioned matter. This Moses distinctly asserts, Plato and his adherents maintain, and ourselves have been taught to believe.”
Such was the doctrine of the schools that professed the eternal nature of matter. Other philosophers supported as warmly a different opinion. Thales of Miletus, Zeno of Citium, Xenocrates, and Dicearchus the Messenian, insisted that the human race had a first origin at a period when mankind did not exist. According to this hypothesis, the universe is an emanation or extension of the essence of the Creator. Zeno and the Stoics attribute this creation to the universal elements of fire and water. Anaximander the Milesian asserted that the primitive animals were formed of earth and water mixed together, heated and animated by the solar rays; these aquatic creatures became amphibious, and were gradually transformed into the human races. Strange to say, this extraordinary idea has found proselytes even in our days, and was advocated by Professor De Lamark in his Zoological Philosophy. This fancy pervades the poetry of the ancients. Homer makes Tethys, the wife of Ocean, the daughter of Uranus and Terra, the first parents; and Hesiod, in his Cosmogony, raises Venus and Proteus from the foam of the sea.
The vital and intellectual fire of the ancients that animated all living beings was admitted by most of their physicians, especially by Hippocrates, Galen, and Aretæus. Aristotle describes an universal creative agent in all the elements, the source of life upon earth, and of the celestial movements in the firmament. Descartes, in modern times, maintained that a vital flame existed in the heart of every animal. This fire, and the genial warmth that it diffused, was considered the soul of the universe; and on this subject Gassendi expresses himself as follows: “Si quis velit talem calorem etiam animam dicere, nihil est similiter quod vetet.”