is produced in its condition. And this change is produced, not by any force or principle which is superadded to the material of the seed, and which, therefore, can be supposed to exist independently of the seed, but by the inherent activity of the substances composing it, set in motion by heat and moisture. The result which we see — the change that has taken place, is the manifestation of this activity; the effect entirely of the nature and arrangement of the different substances composing the seed, together with the peculiar circumstances in which it has been placed and acted upon.

It is evident, that after the first change in the condition of the seed, it cannot be the same thing it was before that change. It is another thing. Now, besides heat and moisture, it is in the presence of other inatter; of the solid materials of the soil; of salts held in solution by water, by all of which it is more or less affected. Therefore, the seed is undergoing in the earth a constant, a perpetual change. Perhaps at no two seconds of time is it the same identical thing. The result of all this is the growth of the seed. It springs, in consequence, above the earth, and is then placed in close relations with other bodies. It meets with light, with the oxygen and carbonic acid of the atmosphere, with a larger quantity of heat, and with electrical currents. It is subjected to impulses on its frame from winds, rains, and so on. From these causes, other changes take place,-developed in leaves, bark, buds, flowers, and finally, (to come back to the point of the circle from which we set out), seeds, fitted, in their turn, to produce the like phenomena under the like circumstances.*

This series of cause and effect may be broken upon, and then we have other phenomena. If the seed in the drawer should there meet with moisture and heat, it would put on the very same changes that first occur when it is planted in the earth ; but having gone through these, and not meeting with a constant supply of moisture and those other substances necessary for its evolution, it passes, of necessity, into other changes, and is decomposed. It is thus, by some eruption of the order of nature, that all her monstrosities are produced. In her esta. blished order she is always regular, beautiful and harmonious.

In most vegetables, and in some animals, the process of generation is confined to one individual. T male organs supply to the female a certain substance which seems to be essential, and without which the ovum, or seed, is not fitted for further development. The same thing holds where the sexes are in different individuals. The semen of male animals answers precisely to the pollen of plants ; as does the uterus of the female to the earth, which is the matrix of the seed. Therefore, it is plain, that the same reasoning will apply to the formation of the ani. mal organization, that are applied above to the vegetable.

But “ life cannot be the result of organization, because the organiza. tion itself is the effect of life.” This is but a poor piece of sophistry. It is as if one should say, 6 combustion cannot be the cause of the union of oxygen and carbon, for their union is the cause of the combus. tion." The actions of life result from the inter-penetration of the

* A bien considérer les choses, la nutrition et la generation sont deux modes du mème phénomène.- Massey.

solids by the nutritive fluid. Certain relations exist between the two, essential to those results which characterize life as differing from other chemical actions. If these relations are destroyed, chemical actions still go on, but they differ from those of life, and they end in different results : for life is not combustion, nor fermentation, nor putrefaction, nor eremacausis, (to borrow a word from Liebig), nor any other sort of chemical action but its own. It is a chemical action sui generis, end. ing in certain specific results, and differs from all other sorts of chemical actions, as all of the above mentioned differ from one another. The results which characterize vital actions are the formation of an ovum in the parent; evolution, or the formation of the different tissues and organs; birth, or the separation of the embryo from the parent; growth until maturity; gradual decay; and necessary death, or the passage from one species of chemical action into another. As long as certain relations between the nutritive fluids and the solids are maintained, life is a necessary act. As long as the organization of the acorn is perfect, it is fitted, if placed in the earth, to become an oak. The embryo is in a condition analogous to the acorn in the earth; and as long as its organization is unimpaired; as long as it receives its supply of nutritive fluid, it will not only grow and live, but growth and life are the inevita. ble and necessary effects,— just as much so, as an explosion is a neces. sary result on the contact of gunpowder and fire.

There was unquestionably a time when no living being existed on the earth. From some unknown combination of circumstances that occurred in lost geological eras, carbon united with water, organic matter was formed from inorganic, and life commenced. As these circumstances were general, doubtless many myriads of living beings were at the same time produced: but, accordingly as the circumstances varied in some particulars in different cases — according to the action of external forces upon them- would there necessarily be some modification of existence, and of the directions which the vital actions, once set in motion, would assume. These primary organic beings may be com. pared to the ova of plants and animals, all of which, to whatever class they may belong, are closely allied in external form and chemical constitution.* But these ova are situated differently; they are evolved under very different circumstances; hence, the immense variety of forms produced. From these general causes, and from the progression of change in the constitution of the earth, those modifications have arisen, which we have generalized into varieties, species, genera, orders, classes, divisions and kingdoms.

This question is not one the solution of which may be a matter of indifference. Why not (we have heard it said) study the science of life as we study other sciences --collect the phenomepa, and arrange them in the order of cause and effect, but leave the question of the essence of

* The nearest approach which the vegetable and animal kingdoms make to each other, is not in the most perfect vegetable and the lowest or simplest organized animal, but in the lowest and rudest forms of both kingdoms, and likewise in their ova. To use a metaphor of Coleridge, they (the two kingdoms) are “two streams from the same fountain indeed, but flowing, the one due west, and the other direct east.”

life as one we cannot fathom? We answer, that, by so doing, we make a wrong start ; — we commence with an hypothesis which is false : be. cause, the very main fact, the key-fact to the right understanding of all the rest, is not comprehended in the scheme. The hypothesis of a "vital force,” as a thing independent of the substances manifesting vital phenomena, is an error, and the parent of innumerable others ; - -chi. mæra chimæram parit. Well and consistently may physiologists reject the splendid discoveries of modern chemistry, if, à priori, be assumed the existence of a force which can and does resist, pervert and control the chemical forces of matter.* All our inferences concerning the processes of digestion, respiration, secretion, nutrition, &c., must be surren. dered, for they are literally worthless : we have labored in a barren field. But, in truth, in thus referring vital phenomena to a mysterious principle of which we can form no idea, do we act more philosophically than the Indian who refers all natural operations to the Great Spirit, or than the old woman who refers every thing to the Will of Providence ? Such references may indeed be very true, but certainly have no claim to be considered as scientific explanations.

Error, when it has once sprung up in the human mind, is not easily eradicated; especially, if sown in early life, nourished during our edu. cation, and strengthened by the influence of great names. The history of philosophy is a record of this truth. Phenomena were once ex. plained by a horror vacui or quinta essentia. Astrology survived many years the birth of astronomy, as, likewise, did alchemy that of chemistry. From this last science, also, may we draw an illustration apposite to the matter in hand. All acquainted with the science must remember the doctrine of Phlogiston—the principle of levity and inflammability. When a metal, after being burned, weighed more than before, and was no longer inflammable, it had lost its phlogiston ; — when the calx, after being mixed with charcoal, was reduced to the metallic state, the metal had regained its phlogiston from the charcoal. Lavoisier overthrew this doctrine, by demonstrating the true causes of the phenome. na; yet many, who receive without hesitation the doctrine of a vital principle, can look back with wonder upon the obstinacy of Priestley, who maintained the exploded theory to his dying day.

Of a “vital principle,” however, we can frame no more distinct notions than we can of phlogiston. As soon as we separate these principles from the substances which manifest the phenomena, they are words, and nothing more.

* Il s'en faut beaucoup, à notre avis, que la question que nous venons d'examiner soit une chose oiseuse. Si nous avons cru devoir la prendre au sériGux, c'est que le système que nous combattons, savoir que presque toutes les fonctions dont il a été fait mention dans les précédentes considérations, ne constituent ni des phénomènes physiques, ni des phénomènes mécaniques, ni des phénomènes chimiques ; c'est que ce système, repétons-nous, ne tend à rien moins qu'à frapper d'une nullité anticipée toutes les recherches, toutes les expériences, physiques, mécaniques ou chimiques que les physiologistes pourront entreprendre pour expliquer ces fonctions. Or, nous le demandons, quel serait le sort de la physiologie, sur quel progrès pourrait-elle compter si l'on interdisait à ceux qui la cultivent le champ des expériences de ce genre.Bouillard, Journal de Med. et Chirurgie, tom. iii., p. 464-Note.

A metal, after being burned, loses its “phlogiston ;" - organic matter, after undergoing certain changes, loses its “ vital principle ;" — the calx, burned with charcoal, is reduced to the metallic state, having regained its phlogiston ;-organic matter, being digested, becomes a part of the living being, having regained its “vital principle.” The parallel is perfect.

Another obstacle to the overthrow of long-received opinions, is our fondness for whatever is mysterious. To some minds, the nakedness of truth is appalling, - the roseate twilight of poetry being far more charm. ing and attractive. It gladdens the imagination to occupy itself with what we deem the judgment cannot reach, and we shall scarcely take the trouble to fathom a subject which is particularly pleasing to the imagination. Superstition soon usurps the throne of reason; and ques. tions, in themselves perfectly innocent,— questions, that it is the duty of philosophy to propound, and, if it can, to answer,- become thus to be regarded with a holy horror. But this factious mystery, with which we enshroud natural objects, is the bane of science, whose object it is to lay bare the train of phenomena in their natural order of sequence. It, besides, diverts the mind from the perception of that great, that eternal mystery, which lies at the bottom of all things. “ All is wonderful, or nothing is.” The existence of a grain of sand, with its powers and capabilities, is as incomprehensible and as wonderful as the existence of a star. He who recognizes this great truth, will smile at all human efforts to aggrandize what is already infinite, or to render more sacred the awful mystery of the universe. If we must have mystery, let us seek it there - in “that which at bottom appearance," and remember always, that, boni viri nullam oportet causam esse, præter veritatem.

Part Second.


I.--Elements of Materia Medica and Therapeutics. By EDWARD Bal.

LARD, M. D., &c. and ALFRED Baring GARROD, M. D., &c.; with Additions and Alterations, by R. A. GRIFFITH, M. D. Philadelphia, Hogan & Thompson, 1816; large 8vo., pp. 516.

This work, according to the statement of the authors in their preface, was brought out in England to answer the demands of physicians and students for some work containing the valuable matter embodied in the large works on the subject, unencumbered with extrinsic matter. The writers desire that it should be looked upon as strictly elementary, and in so far as the description of the drugs is concerned, nothing more than a compilation. The anthors have introduced the officinal articles from the British Pharmacopeas, and have adopted, under the head of each substance, the same kind of arrangement as that of Edwards and Vevaseur, Pereira, &c.; that is, giving the title, physical properties, preparation, chemical composition, chemical relations, operation, uses, dose, officinal preparations, &c.

After a very brief notice of the general principles and of the grounds of classification, with an interesting notice of the properties of the clas. ses, and of the chemical and other relations of medicinal substances, our authors enter upon the proper subject of their work—the account of particular medicines. The substances are arranged, according to their natural relations, in the inorganic, vegetable and animal kingdoms; an arrangement that possesses the advantages of presenting some interest. ing relations between substances, often indicating analogies in chemical properties, and suggesting applications which could not be anticipated from an acquaintance with any other arrangement. Take vegetable sub. stances, for example, of which the “activity and kind of operation” may be predicted from the structure and affinities of the plants from which they are obtained. Plants are grouped together from certain affinities in structure, and experience has established the general law, that, when a group is a very natural one, the medicinal qualities of every member of it are very analogous. This seems to depend upon the fact that the external form is dependent to some extent upon the internal organisa. tion, and it is also on this internal organisation that the elaboration of the peculiar principles, that give them their activity, depends. As es. amples we have tho Solanaceæ, Papaveraceæ, Rosaceæ, &c., in which all the species partake to some extent of the medicinal properties which

« ForrigeFortsett »