Part 2

If we strictly examine the immense series of living bodies, we shall see the vital properties gradually augmenting in number and energy, from the lowest of plants to the first of animals, man; we shall see the lowest plants obedient to vital and physical properties; all plants are governed only by these, which, in them, consist of insensible contractility and organic sensibility; the lowest animals begin to add sensible organic contractility to these properties, afterwards animal sensibility and contractility. We know the expression of Linnæus, which he has used to characterize minerals, vegetables, and animals. The following would be more correct: 1st. physical properties for minerals; 2d. physical properties and organic vital properties, except[2] sensible contractility, for vegetables; 3d. physical properties, all the organic vital properties, and the animal vital properties, for animals.

[2] Several plants certainly possess a considerable degree of sensible organic contractility; the mimosa pudica (sensitive plant) is a well known example, though there are several others that enjoy this property to almost as great an extent; particularly the hedysarum gyrans, the oxalis sensitiva, and the berberis vulgaris. "A very remarkable degree of irritability, not exceeded by the sensitive plant, exists in the flowers of the barberry, (berberis vulgaris.) When these are fully expanded, the stamens are found spread out on the inside of the corolla. In this situation, if the inside of the filament be touched with a pin or straw, it instantly contracts and throws the anther violently against the stigma. This fact, which has been particularly described by Dr. Smith, in the English barberry, is not less remarkable and distinct in the American varieties of the shrub." Bigelow's Florula Bostoniensis. _Tr._

Man and the neighbouring species, which are the particular object of our researches, enjoy then evidently, all the vital properties, some of which belong to organic life, the others to animal life. 1st. Organic sensibility and insensible contractility have all the phenomena of the capillary circulation, of secretion, of absorption, exhalation, nutrition, &c. evidently dependant upon them in a state of health. In treating, therefore, of these functions, we must always ascend to these properties. In the state of disease, all the phenomena that suppose a disorder in these functions, are clearly derived from an injury of these properties. Inflammation, formation of pus, induration, resolution, hemorrhage, unnatural augmentation or suppression of secretions; increased exhalation, as in dropsies; diminished, or wholly wanting, as in adhesions; absorption, disordered in some way or other; nutrition, altered more or less, or presenting unnatural phenomena, as in the formation of tumours, cysts, cicatrices, &c.: these are morbid symptoms, that evidently suppose some injury or disorder in these two preceding properties. 2d. Sensible organic contractility, which, like the preceding, is not separated from the sensibility of the same nature, governs especially in a state of health, the movements necessary to digestion and the circulation of the great vessels, at least for the red and black blood of the general system, for the excretion of urine, &c. In the state of disease, all the phenomena of vomiting, of diarrhœas, and a great part of those numberless ones of the pulse, may ultimately be referred to a disorder of the sensible organic contractility. 3d. All the external sensations, those of seeing, hearing, smelling, tasting, and feeling, and the internal, as those of hunger, thirst, &c. are derived in a state of health from the animal sensibility. In disease, what part does not this property perform? Pain and its innumerable modifications, itching, smarting, tickling, the sensation of heaviness, weight, lassitude, throbbing, pricking, pulling, &c. &c. are not these only different alterations of animal sensibility? A hundred different words would not express the diversity of painful sensations that morbid affections bring with them. 4th. Animal contractility is the principle of locomotion and the voice; convulsions, spasms, palsies, &c. are derived from an augmentation or diminution of this property. Examine all the physiological and all the pathological phenomena, and you will see that there is no one which cannot be ultimately referred to some one of the properties of which I have just spoken. The undeniable truth of this assertion, brings us to a conclusion not less certain in the treatment of diseases, viz. that every curative method should have for its object the restoration of the altered vital properties to their natural type. Every remedy, which, in local inflammation, does not diminish the augmented organic sensibility; which, in œdema and dropsy, does not increase this weakened property; and which does not reduce animal contractility in convulsions, and elevate it in paralysis, fails in its object, and is contraindicated.

To what errors have not mankind been led in the employment and denomination of medicines? They created deobstruents, when the theory of obstruction was in fashion, and incisives, when that of the thickening of the humours prevailed. The expressions of diluents and attenuants, and the ideas that are attached to them, were common before this period. When it was necessary to blunt the acrid particles, they created inviscants, incrassants, &c. Those who saw in diseases only a relaxation or tension of the fibres, the _laxum_ and _strictum_ as they called it, employed astringents and relaxants. Refrigerant and heating remedies were brought into use by those who had a special regard in diseases to an excess or a deficiency of caloric. The same identical remedies have been employed under different names according to the manner in which they were supposed to act. Deobstruent in one case, relaxant in another, refrigerant in another, the same medicine has been employed with all these different and opposite views; so true is it that the mind of man gropes in the dark, when it is guided only by the wildness of opinion.

There has not been in the materia medica, a general system; this science has been governed by the different theories that have successively predominated in medicine; each has, if I may so express myself, flowed back upon it. Hence the vagueness and uncertainty that it presents at this day. An incoherent assemblage of incoherent opinions, it is perhaps of all the physiological sciences, that which best shows the caprice of the human mind. What do I say? It is not a science for a methodical mind, it is a shapeless assemblage of inaccurate ideas, of observations often puerile, of deceptive remedies, and of formulæ as fantastically conceived as they are tediously arranged. It has been said that the practice of medicine was disgusting; I add further, that it is not in some respects the study of a reasonable man, when its principles are derived from the greatest part of the works on the materia medica. Take away those medicines, the effect of which is known only by accurate observation, as evacuants, diuretics, sialagogues, anti-spasmodics, &c. those consequently that act upon a particular function; what knowledge have we of the remainder?

It is, without doubt, extremely difficult at present to class remedies according to their modus operandi; but it is undeniable that all have for their object, the restoration of the vital forces to the natural type, from which they have been driven by disease. Since the morbid phenomena may be considered as different alterations of these forces, the action of remedies should also be viewed as the means by which these alterations are to be brought back to the natural type. Upon this principle, each of the properties has its class of appropriate remedies.

1st. We have seen that there is in inflammations an increase of organic sensibility and insensible contractility; diminish then this increase by cataplasms, fomentations, and local baths. In some dropsies, in white-swellings, &c. there is a diminution of these properties; raise them by the application of wine and all those substances that are called tonics. In every species of inflammation, suppuration, tumours of different kinds, ulcers, obstructions; in every alteration of secretion, exhalation, or nutrition, the remedies act peculiarly upon the insensible contractility, to increase, diminish, or alter it in some way. All those that are called resolvents, tonics, stimulants, emollients, &c. act upon this property. Observe, that these remedies are of two kinds: 1st. general; as wine, ferruginous substances, oftentimes the acids, &c.; these re-animate insensible contractility, and give tone to the whole system: 2d. particular; thus this property is separately excited by nitre in the kidnies, mercury in the salivary glands, &c.

2d. Many remedies act particularly upon the sensible organic contractility; such are emetics, which produce a contraction of the stomach; cathartics, and drastics especially, which create a strong contraction of the intestines. Art does not excite the heart in the same manner as these viscera; we do not artificially increase its movements as we do those of the stomach in gastric diseases. It will, perhaps, hereafter be attempted, especially if it is true that fever may often be a method of cure, and then it will not, I think, be difficult to find the means of effecting it. At other times, we have to diminish sensible organic contractility, and then remedies are employed that act in a manner opposite to the preceding, as in stopping vomitings, in diminishing intestinal irritation, &c.

3d. Animal sensibility has also remedies that are peculiar to it. But they act in two ways—1st. in diminishing pain in the part where it is seated, as different applications upon tumours, obstructions, &c.: 2d. in acting upon the brain that perceives the pain; thus all narcotic preparations, taken internally, remove the sensation of pain, while the cause still subsists. In cancer of an ulcerated uterus, the disease continues its progress with activity, but the prudent physician stupifies the brain so much, that it is incapable of perceiving it. It is essential to distinguish accurately these two actions of remedies upon the animal sensibility. They are totally different from each other.

4th. Medicinal substances have also their influence on animal contractility. Every thing that produces an active excitement on the external surface of the body, as vesicatories, frictions, smarting, &c. tends to re-animate in paralysis this benumbed faculty. All those substances that paralyze the cerebral action, prevent the brain from governing the muscles of animal life; when these muscles, therefore, are convulsively agitated, these substances are true anti-spasmodics.

In presenting these observations, I do not mean to offer a new plan for the materia medica. Medicines are too complicated in their action to be arranged anew, without more reflection than I profess as yet to have bestowed on the subject. Moreover, an inconvenience common to every classification, would here present itself: the same medicine acts often upon many vital properties. An emetic, while it brings into action the sensible organic contractility of the stomach, excites the insensible contractility of the mucous glands, and oftentimes the animal sensibility of the nervous villi. The same observation may be made with regard to the stimulants of the bladder, of the intestines, &c. My only object is to show, that in the action of substances applied to the body to heal it, as in the phenomena of diseases, every thing must be referred to the vital properties, and that their augmentation, diminution, or alteration, are ultimately the invariable object of our curative method.

Some authors have considered diseases only as increased strength or weakness, and have consequently divided medicines into tonics and debilitants. This idea is true in part, but it is false when we generalize it too much. For every vital force there are means proper to raise it when too much diminished, and to lessen it when too much elevated. But tonics and debilitants are certainly not applicable to every case. You would not weaken animal contractility, augmented in convulsions, as you would insensible organic contractility increased in inflammation; neither would you increase them by the same means. The morbid phenomena that organic contractility and animal sensibility experience, are not cured by the same method. There are medicines proper for each vital force. Moreover, it is not only in increase or diminution that the vital forces err, but they are besides disordered; the different modifications that insensible contractility and organic sensibility can undergo, produce in wounds and ulcers a diversity of suppuration, in glands a diversity of secretion, in exhaling surfaces a diversity of exhalations, &c. It is necessary, therefore, that medicines should not only diminish or increase each of the vital forces, but that they should moreover restore them to the natural modification from which they have been altered.

What I have just said is particularly applicable to the strictum and laxum of many authors, who every where see but these two things. The strictum may be properly applied to inflammation, the laxum to dropsies, &c.; but what have these two states of the organs in common with convulsions, with disorder of the intellect, with epilepsy, with bilious affections, &c.? It is the peculiarity of those who have a general theory in medicine, to endeavour to bend every phenomenon to it. The fault of generalizing too much, has been perhaps more injurious to science, than that of viewing each phenomenon separately.

These observations are, I think, sufficient to show, that every where in the physiological sciences, in the physiology of vegetables and of animals, in pathology, in therapeutics, &c. there are vital laws, that govern the phenomena which are the object of these sciences; and that there is not one of these phenomena that does not flow from these essential and fundamental laws, as from its source.

If I should take a survey of all the divisions of physical sciences, you would see that the physical laws were ultimately the sole principle of all their phenomena; but this is so well known that it is not necessary to do it. I will consider an important subject, and one to which we are naturally led by the preceding observations. I mean, a parallel between physical and vital phenomena, and consequently between physical and physiological sciences.

III. _Characteristics of the vital properties, compared with those of the physical._

When we consider, on one side, the phenomena which are the object of the physical sciences, and those that are the object of the physiological, we see how immense is the space that separates their nature and their essence. But this difference arises from that which exists between the laws of the one and the other.

Physical laws are constant and invariable; they are subject neither to augmentation or diminution. A stone does not gravitate towards the earth with more force at one time than another; in every case marble has the same elasticity, &c. On the other hand, at every instant, sensibility and contractility are increased, diminished, or altered; they are scarcely ever the same.

It follows, therefore, that the physical phenomena are never variable, that at all periods and under every influence they are the same; they can, consequently, be foreseen, predicted, and calculated. We calculate the fall of a heavy body, the motion of the planets, the course of a river, the ascension of a projectile, &c.: the rule being once found, it is only necessary to make the application to each particular case. Thus heavy bodies fall always in a series of odd numbers; attraction is in the inverse ratio of the square of the distances, &c. On the other hand all the vital functions are susceptible of numerous variations. They are frequently out of their natural state; they defy every kind of calculation, for it would be necessary to have as many rules as there are different cases. It is impossible to foresee, predict, or calculate, any thing with regard to their phenomena; we have only approximations towards them, and even these are often very uncertain.

There are two things in the phenomena of life, 1st. the state of health; 2d. that of disease; hence there are two distinct sciences; physiology considers the phenomena of the first state, pathology those of the second. The history of the phenomena in which the vital forces have their natural type, leads us to consider as a consequence, those phenomena that take place when these forces are altered. But in the physical sciences there is only the first history; the second is never found. Physiology is to the movements of living bodies, what astronomy, dynamics, hydraulics, hydrostatics, &c. are to those of inert ones; but these last have no such correspondent sciences as pathology. There is nothing in the physical sciences that corresponds to therapeutics in the physiological. For the same reason, every idea of medicament is absurd in the physical sciences. The object of a medicament is the restoration of properties to their natural type; but, the physical properties, never losing this type, have of course no need of restoration.

We see then that the peculiar instability of the character of the vital laws is the source of an immense series of phenomena, which form a peculiar order of sciences. What would become of the universe, if the physical laws were subject to the same commotions and the same variations as the vital? Much has been said of the revolutions of the globe, of the changes that the earth has undergone, of the overthrows that ages have gradually brought about, and upon which ages have accumulated without producing others: but you would see these overthrows and these general commotions in nature at every instant, if the physical properties had the same character as the vital.

For the same reason, that the phenomena and laws of the physical and physiological sciences are unlike, the sciences themselves are essentially different. The manner of presenting the facts and of prying into their causes, the experimental art, &c. every thing bears a different stamp; and it is absurd to confound them. As the physical sciences were perfected before the physiological, mankind thought that they could illustrate the latter by connecting them with the former; but they have confused them; and this was inevitable, for the application of the physical sciences to physiology, was the explication of the phenomena of living bodies by the laws of the inert. Here then is a false principle, and all the consequences drawn from it must be erroneous. Let us leave to chemistry its affinity, and to physics its elasticity and gravity, and let us employ in physiology only sensibility and contractility; I except, however, those cases where the same organ becomes the seat of vital and physical phenomena, as the eye and the ear, for example. It is on this account, that the general character of this work is wholly different from those on physiology, and even that of the celebrated Haller. The works of Stahl illustrate well the advantage of neglecting all those pretended accessory aids, which overthrow the science in attempting to support it. But as this great physician had not analyzed the vital properties, he could not present their phenomena in their true point of view. Nothing is more vague and indefinite than the words, _vitality_, _vital action_, _vital influx_, &c. when we do not precisely limit their meaning. Suppose that mankind had created some general and vague words, which were to correspond to all the non-vital properties, and which gave no precise or definite ideas; if you were every where to use these terms, if you did not determine that which belonged to gravity, that which depended on affinity, and that which was the result of elasticity, you would never be understood. Let us say as much in regard to the physiological sciences. The art is much indebted to many physicians of Montpellier for having deserted the theory of Boerhaave, and having followed in preference that given by Stahl. But in leaving a bad path, they have taken another so tortuous, that they will never, I think, find its termination.

Ordinary minds, in reading, stop at insulated facts that are presented; they do not embrace, at one view, the principles of the work. Oftentimes the author himself incautiously follows the impression given to a science in the age in which he writes. But the man of genius every where pauses at this impression, which should be henceforth entirely different in physical and physiological works. It is necessary to use a different language; for most of the words that are carried from the physical into the physiological sciences, continually refer to ideas that have no connexion with them. You see the living solids constantly undergoing composition and decomposition, every moment taking and rejecting new substances; on the other hand, inert bodies remain the same, and keep the same constituent principles, until friction and other causes destroy them. So in the elements of inert bodies, there is a constant uniformity, and an invariable identity in their principles, which is known when they have been once analyzed; whilst the principles of the living fluids are so continually changing, that it is necessary that many analyses should be made, under every possible circumstance. We shall see the glands and exhaling surfaces pour out, according to the degree of their vital forces, a great variety of modifications of the same fluid; what do I say? they pour out a variety of fluids really different; for are not the sweat and the urine poured out under one circumstance, and the sweat and the urine under another, two distinct fluids? There are a thousand examples that would incontestably establish this assertion.

It is the nature of vital properties to exhaust themselves; time wastes them. Elevated in the commencement of life, they remain stationary at the adult age, and afterwards are debilitated and become nothing. Prometheus, it is said, having formed some statues of men, snatched fire from heaven to animate them. This fire is the emblem of the vital properties; while it burns, life is supported; when it is extinguished, it ceases. It is, then, a part of the essence of these properties, to animate matter for a determinate time only; hence there are necessary limits to life. On the other hand, the physical properties, constantly inherent in matter, never abandon it; so that inert bodies have no limits to their existence, but what accident gives to them.

By nutrition the particles of the matter of inanimate bodies pass into living bodies, and vice versa; and we can evidently conceive that this matter has been endowed through an immense series of ages with physical properties. These properties are given to it at the creation, and will leave it only when the world shall end. This matter, in passing into living bodies, in the space that separates these two epochs, a space that immensity only can bound, this matter, I say, becomes possessed, at intervals, of vital properties, which are then united to physical properties. Here, then, is a great difference in matter, with regard to these two kinds of properties; one it enjoys by intermissions only, the other it possesses constantly.