cate nothing else than the shallowness and self-sufficiency of their authors. After an examination of its contents, however, we feel it right to state that the book cannot be justly referred to either of these categories. It contains a good deal of matter which will be novel and interesting to the general reader, gleaned from the writings of Müller and other physiologists and psychologists; and this is arranged in a manner that will no doubt be attractive to such as have not previously thought deeply on the subjects which the work embraces. Although we cannot give it very high praise, yet, on the other hand, we do not feel called upon to pass a severe judgment upon it. The author enters into his subject in a good spirit; that of endeavouring to convey some definite information upon it to those "who are sometimes mystified or shallowly enlightened by the confident explanations of materialists, over-chemical chemists, phrenologists, and mesmerists." He laments, not unreasonably, that so little can be said in explanation of its mysteries; "still," as he justly remarks,

"It is generally useful to know what there is that we do not know, and how far explanation may be carried, especially that we may avoid that too common disposition to throw a veil of mystery, and a sort of almighty incomprehensibility, over subjects which are really perhaps capable of reduction to the effect of general laws, without the possibility of detracting from that reverence which belongs to the mysterious omnipotence of the Deity."

The work consists of three parts: the first treating of Life, the second of Mind, and the third of the Combined Phenomena of Life and Mind. Notwithstanding our disagreement with the author on many points, we regard his treatise as on the whole well adapted to his object, and as likely to do good by the information it imparts and the incitements which it offers to a deeper study of the phenomena of which it treats.

ART. XI.-Metastasi Riprovate dalla Struttura dei Tessuti e dalle funzioni dei Medesimi. Tratto di G. B. BELLINI, Maestro Operatore in Santa Maria Nuova. -Firenze, 1845.

Metastasis Disproved by the Structure and Functions of Tissues. By G. B. BELLINI, Operating Surgeon in the large Hospital of Florence.— Florence, 1845.

Or this work one fasciculus only has reached us. Its object is to prove that what is generally considered to be metastasis is not so, but a new disease generated in the part supposed to be the seat of metastasis; that the functions of the absorbent and circulatory systems would explain the fact of morbid matter being taken from one part and affecting the general system, but not setting up a disease confined to one organ or tissue; that many supposed instances of metastasis are contemporaneous attacks in different parts, or mere extension of disease; that others are simple instances of reflex nervous irritation, or excitement of some organ which has to do the duty of another, whose functions are interfered with by disease.

It would be unfair to criticise the reasoning of Dr. Bellini before the completion of his work. Our readers can form their own opinions of its nature and value from the statement we have just given of its objects.

THE

BRITISH AND FOREIGN

MEDICAL REVIEW,

FOR OCTOBER, 1847.

PART FIRST.

Analytical and Critical Reviews.

ART. I.

Handbuch der rationellen Pathologie. Von Dr. J. HENLE, Professor der Anatomie und Physiologie in Heidelberg. Erster Band. Einleitung und allgemeiner Theil. Zweite unveränderte Auflage.-Braunschweig, 1846. Manual of Rational Pathology. By Dr. J. HENLE, Professor of Anatomy and Physiology in Heidelberg. First Volume. Introduction and General Part. Second and unchanged edition,-Brunswick, 1846. 8vo, pp. 357.

PROFESSOR HENLE is well known as one of the most distinguished of the distinguished anatomists and physiologists of Germany. As a pathologist, also, he was introduced to our readers some years ago. Still continuing his attention to pathology he has, in conjunction with his colleague Professor Pfeufer, for some time past conducted a journal (Zeitschrift für rationelle Medicin) for the reception of such researches and observations as turn to account the recent progress of pathological anatomy, organic chemistry, physiology, and general anatomy in elucidating the nature of disease and the action of remedies; and now we have from his pen the work before us.

This work, the author tells us in his preface, is an attempt to arrange, in that form which the systematic genius of the Germans requires, the physiological facts which observation of the diseased body has brought to light, together with the theories and hypotheses to which they have given rise, in order to assign to them their place in the history of the development of science.

The fact that, soon after the appearance of this first volume of the work, a second edition was required, affords evidence of the high estimation in which the author's labours are held by his professional countrymen. Participating in this estimation and thinking the work calculated to clear the medical mind of a great deal of misconception and prejudice,

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we bring it under the notice of our readers by means of a pretty full abstract.

In the introduction the first subjects discussed are the Methods in Medicine. Two methods strive for the preference, viz. the empirical and

the rational.

The first method describes the symptoms merely, without inquiring into their cause and intimate connexion; its names are not definitions, but only proper names, and when it uses a word, as, for example, inflammation, it means by it nothing more than the combination of the symptoms of redness, heat, swelling, and pain. The adherents of this method trouble themselves as little with the mode of action of the causes and the remedies as with the conditions on which the symptoms depend. As to remedies they use those which have most frequently been followed by good effects. As in this case the certainty of the methods of cure is not determined by internal arguments, but only by the number of observations the practitioner has made, everything depends on collecting and making use of as extensive a series of observations as possible. Clinical experience is here the rule of treatment. Such is the empirical method.

The second method-the theoretical, physiological, or rational-considers the symptoms in their dependence on each other, and in their connexion with internal changes; and these changes it views as the effects of external influences on the organic structure endowed with peculiar powers. In defining a disease, instead of the symptoms, it describes the state which it believes it has ascertained to be that on which the symptoms depend. It employs names which express the nature of the morbid changes, preferring, for example, such names as "increased plasticity," "hyperæmia,' "stasis," &c., for inflammation, according to the prevailing opinions regarding the essential nature of that morbid process. As to remedies, theoretical medicine investigates their absolute powers and properties and their so-called physiological action, i. e. the mode in which they affect the substance and forces of the organism.

The diagnosis in empirical medicine, like that in the descriptive natural sciences, teaches nothing more than that the particular case, from its external marks, comes under this or that class of known cases; the diagnosis in theoretical medicine is the synoptical and independent history of the particular case. To the empirical physician a definite combination of symptoms, appreciable by the senses, immediately indicates a specific mode of treatment; to the theoretical physician an internal lesion, which is supposed to exist, first indicates the internal change to be effected, and thus, indirectly, the treatment by which it is supposed the required change may be effected.

If it were a question of choice between the two methods, it must be confessed that the empirical in principle promises most certainty; for in a simple comparison of phenomena a mere enumeration of pros and cons— there is less liability to error than in a process of reasoning, in which conclusion is founded on conclusion, and in which a defective link may vitiate the whole chain. Such a fact as that bark cures ague, on the contrary, is in itself so certain that it is quite indifferent how the nature of ague and the mode of action of bark are explained. But such indisputably certain remedies are rare. After an experience of 2000 years, doubts are

still expressed as to the efficacy of medicine at all, and it often happens that in similar cases directly opposite modes of treatment are adopted.

The causes of the small progress in medicine here referred to, Henle considers to be partly subjective and therefore general, and partly objective, i. e. founded on the peculiarities of the object of medicine. That which subjectively or from within ourselves renders experience difficult is, first, a tendency natural to the mind to explain and to arrange facts which are seen to recur in inseparable connexion in the relation of cause and effect, and, for physical effects, to invent a world of metaphysical causes. Hence have arisen the mythological fancies of a materia peccans, a vis medicatrix naturæ, which lie at the bottom not only of the theories of Hippocrates, Galen, Helmont, Stahl, and the so-called natural historical school, but which also constitute the foundation of a physiology still most extensively prevalent. For to define the reaction which supervenes on irritation as a manifestation of an effort of the organism to resist external influences operating prejudicially to it, is merely to declare that every action is a molimen criticum, brought about by the autocracy of the organism for the purpose of removing the enemy. Instead of the condition on which the excitation depends, it is merely giving the object or final cause of it. Secondly, another tendency of our mind which obstructs the advance of knowledge, is to distort and even falsify facts in order to form systems.

To make medicine, so far as it is not yet, a science of experience and observation is, as is known, the object of the new French school, as the head of which Louis is distinguished. Rejecting uncertain tradition, and aware of the errors which result from coming to a conclusion regarding symptoms and the effects of treatment from the observation and superficial remembrance of a small number of cases, Louis requires that the value of the symptoms, as well as the methods of cure, be expressed in figures obtained by the comparison of as large a series as possible of accurately reported observations. This method, called the numerical or statistical, is in fact the only one from the employment of which empirical medicine, as well as other empirical sciences, has any advantage to hope for; inasmuch as logical certainty, in decisions founded on experience, is never obtained, but only a greater or less degree of probability, according to the number of observations and the proportion of affirmatives to negatives. Even the so-called natural laws possess only the highest degree of probability. In other cases the exceptions are too well established to be denied. The affirmed fact thus loses in probability; it expresses itself no more as a law, but only as a rule or norm. value of such a rule, however, is variable, and numerically expressible by the proportion of the affirmative to the negative cases. Such expressions are sought for by statistics.

The

In practical medicine most propositions undoubtedly belong to the disputable. There are few laws; as to rules they are seldom well established, and when they are, they are of uncertain value. If it must be admitted that in similar cases of disease, comprised under one species, a certain symptom is sometimes present, sometimes absent, that certain phenomena precede often a fatal, but sometimes also a favorable issue, &c., then the necessity cannot be got over for correcting such superficial deductions by means of figures.

Calculations like those above indicated, however, do not warrant more than the expression that the facts stand in connexion according to law or rule; they teach nothing of their intimate connexion. That such an intimate connexion exists, and in what manner it does exist, it is the theorizing intellect only which shows and elucidates. Sciences of pure experience and observation, therefore, intentionally abstain from giving judgment on this point, and so also does pure empirical pathology. It knows that ulcers of the intestines and typhus fever, swelling of the spleen and intermittent fever, increased quantity of fibrin in the blood, and the local symptoms of inflammation occur together; but it avoids, or ought to avoid, speaking of the causal connexion of these anatomical changes with the symptoms of the disease. It leaves it, for example, to every one's fancy to consider the ulcers of the intestines as the cause or as the effect of the disease. If, however, knowledge, though so empirically acquired, is to attain to practical application, the question as to the causes can no longer be altogether excluded. However superficially the consideration of the phenomena of disease and recovery, considered in themselves, might be allowed to be passed over, the practical application is not at all conceivable, without the presupposition that in corresponding cases a method of cure and the course of a disease had stood in a certain causal relation.

For these reasons it is delusive to believe that in medicine we can rest on a foundation of pure experience and observation. Every inevitable conclusion is a source of logical error, a source of the deceptive "post hoc ergo propter hoc," against which, as is known, the advocates of opposed methods have never failed to warn each other. Medical experience tells merely that treatment and recovery succeed each other; it is inference and hypothesis to say that the recovery is the effect of the treatment. Though this is an old remark it is necessary to repeat it, because it is always forgotten, and the materia medica in consequence overloaded with remedies which are altogether without power of any kind.

The true touchstone for such hypotheses is experiment, and it is the number of experiments which determines the degree of probability with which a certain action is inferred to be the effect of a certain cause, and with which the same effect may for the future be expected from the same cause. But the problem becomes more complicated when many conditions, especially if opposed to each other, have part in one result. If it is desired to learn the value of one of these conditions, for example, a particular method of cure, it is not sufficient merely to count up the cases in which it has been tried with or without success, but it is necessary to give the number of the cases in which cures were effected by it in proportion to that of those in which it was not employed, or in which some other plan was had recourse to. This is the object of medical statistics, and for an earnest empiricism there is no other way of coming to a decision-the statistical or numerical method and the empirical are one. Another question, indeed, is what the numerical method has done, and is likely to do for practice. This question will be gone into more fully immediately, but at present it may be observed that when the numerical method is not in a condition to guide the choice of remedies, still less so is common so-called experience.

The statistical method is not applicable where there is not at command