The great subject of debate has been, whether obstruction really exists in inflammation. Dr. Wilson, from microscopical observations, is convinced that this is the case. We have said that the conclusion is too general. It seems to fulfil all the idea of inflammation, if, from a disturbed balance in the circulation, the blood is accumulated in a part faster than it is conveyed away by the veins or exhalants. Obstruction is not necessary to explain the phenomena; and in some instances, as we have said, the veins swell, and the discharge from the neighbouring exhalants is increased. Yet we are willing to admit, that in every violent inflammation obstruction does take place; but it is unnecessary to distinguish the circumstances with accuracy, as the explanation of the symptoms or the cure will not be affected by the decision.

The view of inflammation thus given will sufficiently explain almost all the varieties, and give a consistency to the method of cure. The only kind, whose pathology is less obviously derived from the foregoing remark, is erysipelatous inflammation. The only difficulty however arises from the inaccuracy of language. We are accustomed to call those internal inflammations erysipelatous, in which the action of the arteries, so far from being increased, is weakened, and which hastens to gangrene rather than suppuration. There is not, however, the slightest evidence that the state of inflammation internally resembles the external appearance usually denominated an erysipelatous eruption, for this is properly an exanthematous disease, except when in the fauces, where a similar appearance attends the gangrenous throat; but in this case the eruption is a symptom only, and the inactive inflammation hastening to gangrene, the real disease. All the additional explanation will appear from the ratio symptomatum, to which we proceed.

The leading symptom of inflammation is redness, which has been usually explained from the entrance of the red globules into vessels not adapted to their diameters. This error loci we believe really takes place; but, independent of this cause, the redness proceeds in part from slight extravasations in consequence of rupture, but chiefly depends on the greater quantity of the red globules from dilatation and accumulation. It appeared from the microscopical observations of Dr. Wilson, that slight irritation, instead of producing redness, occasioned paleness, in consequence of the more rapid circulation, and that the redness did not appear until the appearances of the blood's motion had ceased. It must be remarked, however, that these experiments are, in part, fallacious. The circulation cannot be observed but in transparent organs; and when vessels are distend-ed so as to admit of considerable accumulation of blood, they are no longer transparent.

Increased heat is another symptom equally characteristic of inflammation, and this was easily explained by the pathologist from the increased circulation, and consequently increased friction. We know, however, that the change in the blood's capacity for heat, which takes place during the circulation, is equally going on during its stagnation, and when a larger quantity is accumulated in a part, the heat given out in consequence of this change must be necessarily greater. On the approach of gangrene the parts are cold; but this change never takes place till the blood has already assumed a livid hue, and of course has yielded all the heat which could be separated in consequence of this change of capacity.

The pain is more easily explained from the distention, and the spasm which also must take place in consequence of the distention. It will be obvious also, that where the vessels are closely confined in membranes, they admit of distention with difficulty, and the pain is proportionally increased. The pain is also in proportion to the sensibility of the organ and the diathesis phlo-gistica, where the disease in a great degree arises from the violent action of the vis a tergo. On both these accounts, the inflammation of the eye is attended with the most excruciating pain. Ligaments and tendons when inflamed are also acutely sensible, though their sensibility is inconsiderable in the sound state. The source of the only other symptom, the swelling, is sufficiently obvious.

The remote causes of inflammation are either general or topical. The general causes are those of fever, determined in their seat by some accidental cause, generally some debility of the part. Inflammations of this kind are usually inflammatory, arising from excess of action in the larger arteries; but in different states of the atmosphere, or rather in different epidemic constitutions, either a less degree of phlogistic diathesis will produce the accumulation, or the balance is destroyed by the loss of tone in the affected part; often not without suspicion of a morbid poison determined to the part, particularly in the putrid sore throat, which seems rather an exanthema than a phlegmasia.

Of the topical causes but a few only are direct stimuli. A thorn in the flesh is one of the most familiar instances of this kind; chemical acrids produce the same effects; but a more frequent cause in the human body is any extraneous body, or any portion of the body deprived of life which acts as such. These continued irritations seem to produce those inflammations, in which, as we have said, there is no decisive evidence of obstruction.

The other topical causes are those of indirect debility, as burning, overstretching, concussions, etc. which we have already shown, with a view to this subject, act by-producing atony. The coup de soleil, at least in this country,, appears to have a similar effect. See Ictus Solaris.

The terminations of inflammation are said to be by resolution, by abscess, by gangrene, and scirrhus; but this offers a very fallacious view of the subject. In fact, the salutary terminations of inflammation are by effusion and abscess; the fatal ones most commonly by haemorrhage and gangrene. Scirrhus is usually a previous disease, and excited to cancer by inflammation.