quarters is no doubt to accumulate a number of truths; but we are in quest of one truth, one uniform, unbroken foundation, and this we can find neither among the Episynthetics nor Eclectics.

The Pneumatic school took one step further in departure from a definite foundation; for whereas hitherto the theories. of disease had contemplated deviation from the normal standard in the several known elements of the body or their properties, heat, cold, dryness, and moisture, the pneumatic sect introduced another element, entitled pneuma, or spirit, to which they assigned the cause of disease, thus building a theory on a basis itself having only a theoretical existence. These were the principal medical schools of antiquity. To them the Arabians cannot be said to have added much, since these were merely the copyists and translators of their predecessors, though they introduced some new substances into practice. They do not appear to have founded any new school, unless we ascribe to them the chemical school. The introduction of chemistry, even in its very imperfect state, was a great step in advance, but merely a step of detail; that is to say, it contributed to enlarge the materia medica, but it established no general law of cure. Even the search after a universal medicine was of this character; it was the search after a particular substance, not after a law or principle. The pursuit was so visionary, that it deserves. not any particular attention; but even if by a stretch of imagination we suppose the object attained, it could scarcely be said to lay a foundation for the theory and practice of medicine, since it would wholly absorb both the science and the art. A universal remedy of disease and preventive of death would itself constitute the whole of therapeutics. But apart from the chimerical nature of the pursuit, it involved such an ignorance of the nature of man and the laws of his being, as to be totally incapable of affording a definite foundation for any method of correcting deviations from the healthy performance of functions appropriate to that nature and regulated by those laws.

We are left equally destitute of any definite foundation by the more recent theories, either spiritual or material. Thus

the spiritual theories of Van Helmont and De Stahl may be held to be true or otherwise. We may contemplate vitality under the idea of a living intelligent principle or soul, or we may regard it as the necessary result of organisation, and at the same time be conscious that we are equally removed on either supposition from any definite foundation of the theory and practice of medicine. Though we were quite sure of the existence of an intelligent uxn, or apx", or vis naturæ, presiding over the human frame and seeking to repel disease, we should still be without a guide to the treatment of it. We cannot regulate the movements of this intelligent principle, nor force it to speak out in order to regulate ours. All that we can do is to minister to the exercise of its powers; but whether our efforts be to help or to hinder, we can only tell by the result, a result in no degree modified by the hypothesis of such a superintending power. And if, on the contrary, we view life as the necessary result of organisation, and every disease as a perturbation of that organisation, we have still to ascertain the character of the perturbation, and the method and principle according to which we may seek to restore the pristine or normal state. Either theory, whether that of spirituality or materialism, affords in itself no clue to treatment; it is a mere theory of physiology or pathology, not a theory of cure.

We need not dwell long on any of the more recent doctrines of the schools: there are, however, two, which may not be wholly passed over. The theory of Dr. Brown, owing to its great simplicity, was very widely adopted. It may be considered a new school of the methodic sect, classifying all diseases under two heads, viz., 1st, excess of excitement, and 2nd, defect of excitement, and classifying treatment and medicines accordingly. But this also is a theory of disease, not a theory of cure, and involves a double theory, viz., that of the disease and that of the action of the medicines, with this additional inconvenience, that in proportion as it simplifies the forms of disease, so must it simplify the available powers of medicine, and regard them not as they really are, infinitely varied, but merely as possessing one or other of the two pro

To esteem so

perties of exciting or allaying excitement. narrow a conception of the materia medica and of the morbid conditions of human nature as a definite foundation for the treatment of the countless forms of disease, would be to construct a pyramid upon its apex.

Similar in its essential character, viz. that of very extensive generalization, appears to be the theory of Broussais, which ascribed a large proportion of the diseases, if not in principle, the whole, to mucous irritation, and met them by the simple remedy of blood-letting. (We do not assert this to be the sum total of his theory or treatment, but its characteristic feature, that which individualised it.) Now, supposing the theory established in its full extent, that all diseases have a local origin and fixed character, consisting of irritation of the mucous membrane, this would be merely a theory of disease, and not a theory of cure; and it would by no means follow from it, that the method of cure should be equally uniform and fixed; for it remains to be shown that the abstraction of blood is the cure for mucous irritation, and still further, that this cure can be effected by the abstraction of blood at so remote a distance as that which intervenes between the external surface of the body and the internal organs. Flattering, there'fore, as the prospect of great simplicity may have been, even at the cost of so much vital power as is implied in making the abstraction of blood the chief therapeutical agent, it cannot be maintained, that even at this cost, a definite foundation has been laid.

It is somewhat indicative of the insufficiency of the various systems which we have thus very briefly reviewed, that they arose in general from each other, not by way of development, but of opposition. Thus the dogmatic by its uncertainty led to the empiric; the empiric, by its want of classification, to the methodic; the incompetency of any one of the preceding systems led to the episynthetic and eclectic; while the more recent schools may be considered merely as modifications of the earlier, chiefly of the pathological and methodical.

These changes, therefore, although extending through centuries, by no means indicate an advancement in medicine,

but rather its low and uncertain state. Had a definite founda tion been laid, we should expect the different theories of successive ages to arise from each other by way of development, for they are not destitute of mutual relation, nor are the characteristic features of all incapable of mutual harmony. Thus, pathology is related to empiricism, empiricism to method. or classification, method to combination and selection. Had the foundation, therefore, been laid, all these forms might actually have existed, but they would have presented themselves under the aspect of development, not of opposition. Had it been laid in pathology, a link would have been established between that science and therapeutics; and classification, combination, and selection would have been also regulated by the same law, whatever it might be. But the difficulty has always been to establish the link between pathology and therapeutics: efforts directed to this end have hitherto proved fruitless, and it is probable they will always remain so.

The proper object of pursuit, is a general law of therapeutics, the discovery of which must be made in the region of therapeutics, that is to say, in the application of medicinal agents to the human constitution. Until we have distinct convictions concerning the source whence we are to derive the object of our search, we may be labouring in a mine rich in its appropriate ore, but utterly destitute of that which we desire. (To be continued.)

PERVERTED ACTION OF THE NERVOUS SYSTEM. IRRITATION.*

This word is here used to denote a morbid condition different from inflammation. In the latter we found the blood-vessels of the part to be chiefly concerned in the morbid change, all the component tissues, however, being, sooner or later, more or less, involved; here the nerves occupy a somewhat similar

We have received several letters requesting us to give at length the symptoms of irritation, so that the general reader may be able to distinguish them from those of inflammation. They will find this done pretty fully in the following paper, which has been taken from Dr. Miller's Principles of Surgery.

pre-eminence; on perversion of their function the diseased state mainly depends. The nervous function is excited and perverted, by an irritative agent, applied either directly or indirectly; pain, and other abnormal sensations, with more or less disturbance of general function, result. The blood-vessels are secondarily involved, but not in a sthenic form and such implication does not effect such an alteration of the local cir culation as to lead to effusion and change of structure thereby. The morbid state may be either local or general.

Local Irritation.-Its signs are negative as well as positive. Little or no increase of blood is to be found in the part, little or no effusion, and no change of structure; little unusual heat, and no swelling, unless indeed there be a shade of tumescence by reason of an unwonted fullness of the fibrocellular tissue;† no redness; but sometimes a paleness of the part, from temporary anæmia there-sometimes a livid hue, from temporary passive congestion. Pain is the prominent symptom-sometimes slight, usually intense, occasionally excruciating. Unlike that of inflammation, as great at the beginning as at last; and not only remittent, but intermittent; worse at one time than at another, and during certain periods altogether absent. The general function of the part is disordered; secretion, for instance, may be either increased or diminished in quantity, or variously altered in quality. As examples of irritation may be mentioned, disordered function and sensation of the rectum, by the presence of ascarides § there-the pain not often great, and usually merged in the sensation of itching; stone in the bladder ultimately leads to various grades of perverted vascular action in the coats, but at first may cause only irritation-the pain in this case is often severe; simple decay of a tooth often

STHENIC.-A term meaning strength, and applied to those diseases which have increased energy and vigour among the prominent symptoms. This term is likewise used to those diseases dependant upon accumulated excitability.

FIBROCELLULAR TISSUE.-The substance immediately beneath the skin, which surrounds and binds together the muscle, blood-vessels, and nerves, and in which the fat of the body is contained.

ANEMIA.-Exanguinity, or a state of bloodlessness.

§ ASCARIDES.-Parasitical worms found in the human body.