mediately suffers an alteration, so that anæmic conditions must ensue. To the stream of lymph also an obstruction may arise, and in this way again deficiency of absorption, tendency to dropsy, &c., be produced.

If we apply iodine to sections of such glands as these, all the diseased parts become coloured red, whilst every part that retains its normal structure merely becomes yellow. The capsule, which consists of connective tissue, the fibrous trabeculae between the follicles, the delicate intrafollicular network which separates the different corpora amylacea, and lastly those follicles which contain normal cells, remain yellow. All the other parts assume the iodine-red hue. If we add sulphuric acid, these parts become of a dark reddish brown, or violet red-or if one hits the mark, pure blue; but if there are still nitrogenous particles present, the colour becomes green or brownish red.

Now, gentlemen, that we have established the classification of morbid disturbances generally according to the difference of action in the tissues, I think of treating more in detail of the process, which the practical physician, according to the ordinary mode of speaking, most frequently meets with, namely inflammation.

Our notions of inflammation have undergone an essential change in consequence of the observations, of which you have now heard a certain part. Whilst until quite recently it was the custom to look upon inflammation as a real entity, as a process everywhere identical in its essence, after I made my investigations no alternative remained, but to divest the notion of inflammation of all that was ontological in it, and no longer to look upon the process as one differing in its essence from other pathological processes, but only to regard it as one differing in its form and course.

In the descriptions given of inflammation by the old

writers-as preserved to us in the dogmatical writings of Galen-among the four cardinal symptoms (calor, rubor, tumor, dolor) heat is, as is well known, the most prominent, for it is the symptom from which the process has acquired its name. Afterwards, in proportion as the question of animal heat in general, and of heat in pathological conditions in particular, withdrew into the back ground, great importance was attached to the redness. And thus it happened that even in the last century, at the time when mechanical theories were in vogue, when especially Boerhaave considered inflammation to consist in an obstruction of the vessels, and in the stasis of the blood consequent upon it, the notion of inflammation was more or less grounded upon supposed conditions of the vessels. After the facts of pathological anatomy had extended their compass, hyperæmia was, especially in France, declared to be the necessary and regular starting point of inflammation. The exclusiveness, with which this view has been maintained even up to our own times, was in a great measure an after-effect of Broussais' views which became the prevailing ones in consequence of the development of the pathologico-anatomical school. Hyperæmia gradually superseded all the other essential symptoms.

A change in the doctrine on a grand scale has really only been attempted by the Vienna school, for they too, like the French school, grounding their system of pathology upon pathological anatomy, have put the products of inflammation in the place of the symptoms of inflammation. What, basing their opinion upon their own experience, they especially had in view, and sought to establish as the essence of inflammation, was the product, which, in accordance with traditional notions, was designated as one which had necessarily proceeded from the vessels-as an exudation. In the old classification of symptoms, the swelling, corresponded pretty nearly with the exudation of the

Vienna school, and it might therefore be said that, as previously, first the heat, and then the redness, had held the first place, so now the swelling occupied the foremost rank. It is only in the more speculative views of the neuro-pathologists that the pain is, as is well known, regarded as the essential and original change in the act of inflammation.

There can be no doubt, but that of these different positions the anatomical doctrine of the Vienna school would be the most correct, if it could be demonstrated, that, as the language of most of the physicians of the present day would lead us to believe, an exudation really does take place, in every case of inflammation; that the swelling is essentially occasioned by this exudation; and especially, that this exudation ought to be regarded as a constant and typical one, and the quantity of fibrine contained in it as a criterion of its inflammatory nature.

I have already, in the previous lectures, endeavoured to shew you, in what a considerably restricted sense the term exudation must be employed, and how essentially the activity of the elements of the tissues themselves is concerned in the appearance of matters, which we certainly must regard as derived from the vessels and deposited in the parts affected. A good deal is, as we have seen, not so much exudation, as, if I may so express myself, an educt from the vessels in consequence of the activity of the histological elements themselves.

Irritation must, I believe, be taken as the startingpoint in the consideration of inflammation, and it is because Broussais and Andral regarded the matter in this light, that I consider the views advanced by them to be the most correct. We cannot imagine inflammation to take place without an irritating stimulus (irritament), and the first

1 The term irritament (Reiz, which, however, sometimes means irritant, stimulus) is intended to express the change (mechanical or chemical, palpable

question is, what conception we are to form of such a stimulus.

We have already seen that the irritation may in general be traced to one of three different sources, according as it is a functional, nutritive or formative irritation which has taken place. Now there can be no doubt, but that functional stimuli (irritaments) do not play an essential part in inflammation, and for the simple reason, that a point upon which all the more recent schools at least are agreed— to the four characteristic symptoms lesion of function (functio læsa) must be added.

If there be a disturbance of function in inflammation, this presupposes that the inflammatory stimulus (irritament) must be of such a nature as to cause changes in the composition of the part which render it less capable of performing its functions. Nobody would expect a muscle which is inflamed, to perform its functions normally; every one supposes that the contractile substance of the muscle has thereby experienced certain changes. Nobody would expect an inflamed gland-cell could secrete normally, but we should look upon the disturbance of secretion as a necessary consequence of the inflammation. Nobody could expect an inflamed ganglion-cell

(anatomical) or molecular) which takes place in a tissue in consequence of the action of an irritant— a change, therefore, which is of a purely passive nature (lesion), and which (subsequently) provokes changes in the neighbouring parts not directly altered by the irritant-the consequence of which is their action, or reaction. This condition, which is an active one, based upon the physiological powers of the parts, represents irritation in the proper sense of the word, and is the starting-point in every form of inflammation. See Archiv f. path. Anat. und Phys. vol. xiv, p. i (Reizung und Reizbarkeit).

The matter will perhaps be rendered clearer by the following familiar illustration-Suppose three people were sitting quietly on a bench, and suddenly a stone came and injured one of them, the others would be excited, not only by the sudden appearance of the stone, but also by the injury done to their companion, to whose help they would feel bound to hasten. Here the stone would be the irritant, the injury the irritament, the help an expression of the irritation called forth in the bystanders.-From a MS. Note by the Author.

or nerve to discharge its functions, or normally to respond to stimuli. The conclusion, therefore, that must in accordance with the commonest experience be necessarily drawn from all this is, that changes must have occurred in the composition of the cellular elements altering their natural functional power. Such changes, when they occur after the application of stimuli which are not powerful enough to destroy the parts at once, or to exhaust their functional power, are only possible when the stimuli are either nutritive or formative. And in fact this conclusion is confirmed by what occurs in inflammation. For now-a-days we find the view is already pretty generally spread, that in inflammation we have in the main to deal with a change in the act of nutrition, nutrition being here indeed regarded as embracing the formative and nutritive processes.

If therefore we speak of an inflammatory stimulus (irritament), we cannot properly intend to attach any other meaning to it, than that, in consequence of some cause or other external to the part which falls into a state of irritation, and acting upon it either directly or through the medium of the blood-the composition and constitution of this part undergo alterations which at the same time alter its relations to the neighbouring parts (whether they be blood-vessels or other structures) and enable it to attract to itself and absorb from them a larger quantity of matter than usual, and to transform it according to circumstances. Every form of inflammation with which we are acquainted, may be naturally explained in this way. With regard to every one, it may be assumed that it begins as an inflammation from the moment that this increased absorption of matters into the tissue takes place, and the further transformation of these matters commences.

This view accords to a certain extent, as you no doubt see, with that which has been maintained by the upholders of the vascular theory, according to which the exudation