NOTE.
I have noticed in the Preface to the Second and Third Editions (S. xiii., p. xii. English Trans.) the subject of the republication here of the preceding pages, which were first printed in Schiller’s Horen (Jahrg. 1795, St. 5, S. 90-96). They contain the development of a physiological idea clothed in a semi-mythical garb. In the Latin “Aphorisms from the Chemical Physiology of Plants” appended to my “Subterranean Flora,” in 1793,—I had defined the “vital force” as “the unknown cause which prevents the elements from following their original affinities.” The first of my aphorisms were as follows:—Rerum naturam si totam consideres, magnum atque durabile, quod inter elementa intercedit, discrimen perspicies, quorum altera affinitatum legibus obtemperantia, altera, vinculis solutis, varie juncta apparent. Quod quidem discrimen in elementis ipsis eorumque indole neutiquam positum, quum ex sola distributione singulorum petendum esse videatur. Materiam segnem, brutam, inanimam eam vocamus, cujus stamina secundum leges chymicæ affinitatis mixta sunt. Animata atque organica ea potissimum corpora appellamus, quæ, licet in novas mutari formas perpetuo tendant, vi interna quadam continentur, quominus priscam sibique insitam formam relinquant.
“Vim internam, quæ chymicæ affinitatis vincula resolvit, atque obstat, quominus elementa corporum libere conjungantur, vitalem vocamus. Itaque nullum certius mortis criterium putredine datur, qua primæ partes vel stamina rerum, antiquis juribus revocatis, affinitatum legibus parent. Corporum inanimorum nulla putredo esse potest.” (Vide Aphorismi ex doctrina Physiologiæ chemicæ Plantarum, in Humboldt, Flora Fribergensis subterranea, 1793, p. 133-136).
I have placed in the mouth of Epicharmus the above propositions, which were disapproved by the acute Vicq d’Azyr, in his Traité d’Anatomie et de Physiologie, T. i. p. 5, but are now entertained by many distinguished persons among my friends. Reflection and continued study in the domains of physiology and chemistry have deeply shaken my earlier belief in a peculiar so-called vital force. In 1797, at the close of my work entitled “Versuche über die gereizte Muskel und Nervenfaser, nebst Vermuthungen über den chemischen Process des Lebens in der Thier und Pflanzenwelt” (Bd. ii. S. 430-436), I already declared that I by no means regarded the existence of such peculiar vital forces as demonstrated. Since that time I have no longer called peculiar forces what may possibly only be the operation of the concurrent action of the several long-known substances and their material forces. We may, however deduce from the chemical relations of the elements a safer definition of animate and inanimate substances, than the criteria which are taken from voluntary motion, from the circulation of fluids within solids, from internal appropriation, and from the fibrous arrangements of the elements. I term that an animated substance “of which the parts being separated by external agency alter their state of composition after the separation, all other and external relations continuing the same.” This definition is merely the enunciation of a fact. The equilibrium of the elements in animated or organic matter is preserved by their being parts of a whole. One organ determines another, one gives to another its temperature and tone or disposition, in all which, these, and no other, affinities are operative. Thus in organised beings all is reciprocally means and end. The rapidity with which organic parts, separated from a complete living organism, change their slate of combination, differs greatly, according to the degree of their original dependence, and to the nature of the substance. Blood of animals, which varies much in the different classes, suffers change sooner than the juices of plants. Funguses generally decay sooner than leaves of trees, and muscle more easily than the cutis.
Bones, the elementary structure of which has been very recently recognised, hair of animals, wood in plants or trees, the feathery appendages of seeds of plants (Pappus), are not inorganic or without life; but even in life they approximate to the state in which they are found after their separation from the rest of the organism. The higher the degree of vitality or susceptibility of an animated substance, the more rapidly does organic change in its composition ensue after separation. “The aggregate total of the cells is an organism, and the organism lives so long as the parts are active in subservience to the whole. In opposition to lifeless or inorganic, organic nature appears to be self-determining.” (Henle, Allgemeine Anatomie, 1841, S. 216-219). The difficulty of satisfactorily referring the vital phenomena of organic life to physical and chemical laws, consists chiefly (almost as in the question of predicting meteorological processes in the atmosphere), in the complication of the phænomena, and in the multiplicity of simultaneously acting forces and of the conditions of their activity.
I have remained faithful in “Kosmos” to the same mode of viewing and representing what are called “Lebenskräfte,” vital forces, and vital affinities, (Pulteney, in the Transact. of the Royal Soc. of Edinburgh, vol. xvi. p. 305), the formation-impulse, and the active principle in organisation. I have said, in Kosmos, Bd. i. S. 67, (English Ed. vol. i. p. 62), “The myths of imponderable matter and of vital forces peculiar to each organism have complicated and perplexed the view of nature. Under different conditions and forms of recognition the prodigious mass of our experimental knowledge has progressively accumulated, and is now enlarging with increased rapidity. Investigating reason essays from time to time with varying success to break through ancient forms and symbols, invented to effect the subjection of rebellious matter, as it were, to mechanical constructions.” Farther on in the same volume, (p. 339 English, and 367 of the original,) I have said, “In a physical description of the universe, it should still be noticed that the same substances which compose the organic forms of plants and animals are also found in the inorganic crust of the globe; and that the same forces or powers which govern inorganic matter are seen to prevail in organic beings likewise, combining and decomposing the various substances, regulating the forms and properties of organic tissues, but acting in these cases under complicated conditions yet unexplained, to which the very vague terms of ‘vital phænomena,’ ‘operations of vital forces,’ have been assigned, and which have been systematically grouped, according to analogies more or less happily imagined.” (Compare also the critical notices on the assumption of proper or peculiar vital forces in Schleiden’s Botanik als inductive Wissenchaft (Botany as an Inductive Science), Th. i. S. 60, and in the recently published excellent Untersuchungen über thierische Elektricität (Researches on Animal Electricity), by Emil du Bois-Reymond, Bd. i. S. xxxiv.-l.)