Elements of Surgery. Robert Liston

mortis, in consequence of the contraction of the vessels, which is well known to occur at that period.

      It has been said that redness is not essential to inflammation; for serous vessels may be altered in size and function by this action, and yet not be sufficiently dilated to receive the red globules of the blood. And, again, that serous vessels may be enlarged so as to admit the red globules; and a part that is colourless when in the healthy state may, in consequence, assume a highly red hue when in an inflamed condition. This may be observed in the cornea lucida, which, when violently inflamed, is pervaded by numerous vessels, visible to the naked eye, distended with red blood, ramifying over the whole of it, and freely inosculating with each other. Some have even supposed that these vessels are newly formed, in consequence of inflammatory action. This opinion is, however, erroneous; as the vessels existed in the cornea previously, and are only increased in size, so as to admit of the accumulation of a sufficient number of red particles to render the vessels visible. The speedy, and, in many cases, instantaneous, appearance of red vessels where they could not previously be observed, decidedly overturns the opinion that new vessels are in such a case formed. New vessels are seldom formed, unless after a breach of structure, or in cases where morbid deposits become vascular. There is no proof of the existence of mere serous vessels in the human body, as any one may ascertain who is accustomed to examine the capillaries with a good microscope. Vessels which are so small as to admit only a very few, say one, or at most two rows of globules, would, of course, appear colourless, and these are what have been called serous vessels. The globules of blood are so small as to be invisible to the naked eye; and vessels carrying only one series of them would appear colourless. No vessels belonging to the sanguiferous system have ever been observed less in character than a blood globule; and this, so far as I have been able to observe, is, as nearly as possible, 1/3000 part of an inch. They appear to be flattened discs; and whether those of the human body have a central nucleus or not, seems, as yet, very doubtful. The

globules are here shown upon a scale of 1/4000 part of an inch, linear, and in different positions. They are represented, as seen in the greater number of microscopes, having a central nucleus. Whether, in the blood of mammiferous animals, or not, this is an optical deception, is not very clearly made out; but in that of reptiles the nucleus is easily demonstrable. The redness then is not from error loci, or in consequence of red particles flowing where none flowed before, but from the capillaries becoming distended and dilated with an unusual quantity of blood, which is stagnated in the central part of the inflamed neighbourhood, the inflammatory focus.

      Throbbing, to a greater or less degree, is always felt in an inflamed part by the patient; and it is frequently so distinct as to be readily perceived by an attentive examination. This arises, probably, from the stagnation of blood in the vessels of the part over-excited, and principally affected by the disease or injury, causing an increase in the collateral circulation; and it is this rapidly increased action around that gives rise to the signs and symptoms, and constitutes, in point of fact, what is known and recognised as inflammation. The sensation of throbbing is not, however, produced entirely by the action of the capillary vessels, but in consequence, also, of the larger trunks in the neighbourhood sympathising with these capillaries, and so having their action increased also. The obstruction of the capillaries in the early stage of inflammation must necessarily cause a greater force of the heart to be expended on the trunks leading to such capillaries; hence the greater impulse and velocity of blood in the circumferential and patent vessels. In fact, when the inflammatory action is extensive or severe, or when the part affected is of much importance to life, the whole circulating system is disturbed, and thus arises the sympathetic excitement of the constitution.

      The incited action of those vessels in the more immediate vicinity of the inflamed part is well marked in cases of Paronychia. There the digital, the radial, and ulnar arteries, with their branches, beat more violently than usual; and with much greater force, though not more rapidly, than the vessels in other parts of the body.

      Swelling is caused by the enlarged and overloaded vessels relieving themselves by effusion of part of their contents into the surrounding cellular texture. The effusion varies in extent and consistence, according to the degree of inflammatory action, and the species of resistance offered; at first it is serous, then mixed with fibrin, and consequently spontaneously coagulable. Cæteris paribus, the greater the resistance, the less the effusion, and the more violent the inflammatory action; the chance of its speedy and favourable termination is also more diminished. Even the enlargement of the bloodvessels produces a certain degree of intumescence previous to effusion. The relief to the vessels by effusion giving rise to swelling, when it occurs in loose cellular tissues, may be considered as a beneficent provision of nature. But in vital organs it may be productive of the most serious consequences; as in these, very slight effusion will often endanger the structure of the organ, destroy its functions, and not unfrequently be attended with fatal consequences.

      The nature of the effused fluid varies according to the degree of violence and advancement of the action, and is also modified by the texture in which that action occurs. It may consist of serum, lymph, blood, or pus. In inflammation, in short, exhalation, though at first diminished, is soon much increased, whilst the powers of the absorbent vessels are diminished, or at least do not maintain their usual relation to those of the exhalants.

      Pain is the next symptom enumerated. Here the very common error of supposing that where there is pain there must always be inflammation may be noticed. Some diseases attended with the most acute pain, as Tic Douloureux and Cramp, are generally unattended with inflammation. Many chronic diseases, too, are accompanied with violent and long-continued paroxysms of pain, without excited circulation of the part.

      This erroneous opinion often gives rise to highly prejudicial proceedings, as—the exhausting, by copious depletions, the vital powers of patients, already enfeebled by continued disease or treatment—the consequent aggravation of the urgent symptoms—and, the then only termination of the disease and of the practice, death.

      Again, it is true that we must bleed, in some cases, with the view of preventing the occurrence of inflammation; yet the prophylactic treatment may be carried too far, as in cases of violent injuries, or after severe operations. In these instances, the immediate abstraction of blood, so far from being beneficial, expedites the dissolution of the patient, or at least greatly retards the cure. Pains arising from local irritations are often treated in a similar way, whilst the removal of the cause would be much more likely to restore the natural action of the parts.

      Though inflammation does not always accompany the sensation of pain, yet the latter, in a greater or less degree, attends inflammatory action; and, perhaps, it is fortunate that it does so. Because, were it not for the occurrence of pain, the patient’s attention would not be directed to the disease; he would continue to use the part as if in health, and the affection would thus be much aggravated. Whereas, according to the existing provision of nature, pain is felt at the commencement of the action, the presence of which the patient is thereby made aware of; and he is compelled to employ such measures for its removal as reason naturally dictates, of which none is more effectual than disusing the affected part. The nerves are thus the safeguards of the various parts of the body in health—their nurses in disease. A part deprived of sensation may be used, even to the destruction of its texture, without producing any impression on the sensorium, and consequently without the animal being conscious of it.

      The presence of pain, as a symptom of inflammation, may be easily explained. The connexion of the vascular with the nervous system is very constant and intimate. Their ramifications accompany each other, and are contained in the same cellular sheath; and without the reciprocal influence of each, neither could perform its functions perfectly. By injecting a limb soon after its separation from an animal, and before its vital heat has departed, spasms of all muscles are sometimes produced; showing the intimate connexion between these two systems. This, however, is distinct from the contractions of the muscular fibre produced by the application of stimuli. In the former case, the contractions are universal, and induced through the medium of the nerves. In the latter, the irritability of the fibre is excited.

      When the circulation is excited, the nerves accompanying the affected vessels are unusually compressed,