The fever about to be described to the reader is known and distinguished by several names, some calling it inflammatory, some symptomatic, and others sympathetic. It is also supposed by some to be idiopathic, that is, to originate at the same time with the local inflammation, and from the same causes. But in other instances, and, indeed, we may say in all ordinary cases, it is produced not directly by the causes which originally produced the inflammation, but in consequence of the sympathy of the whole constitution with the disturbed state of a part

Now, some authorities consider constitutional irritation to be of two kinds, namely, direct and reflected, by which is implied that the first is wholly and immediately derived from the part, commences and is identified with the local mischief, and the constitution has no share in its production. The second, on the contrary, originates in a peculiar morbid state of the constitution to which the injury or inflammation has given birth, or it may be previously existing.

The first is truly symptomatic, never originating spontaneously; and being immediately induced by the local irritation, is capable of being essentially mitigated or arrested by its removal.

The second is occasionally purely idiopathic, and, being oftener the cause than the effect of the local action, is seldom influenced by the local treatment. In the first the local changes are dependent on local causes, in the second they depend on constitutional causes.

As the expression "reflected irritation," if understood in the literal sense, involves the reader in a hypothesis which is, perhaps, not correct, I do not see the advantage in the employment of it. However, used figuratively, it may be as allowable as many other expressions in medical language.

Idiopathic inflammatory fever is said to be always preceded by chilliness. The symptomatic or sympathetic inflammatory fever sometimes takes place so quickly, in consequence of the violence of the exciting cause or of the local inflammation, that no preceding coldness is observable. If, however, the local inflammation be more slowly induced, and consequently operates more gradually on the system, then the coldness is evidently perceived. The symptomatic fever induced by scalding or burning a part is quickly produced, and we have very little time to attend to the earliest period of its formation. On the other hand, the symptomatic fever induced by wounds is excited more slowly, and the period of its formation is longer. This fever is not produced when the inflammation only affects parts in a slight degree, but it makes its appearance if the local inflammation be considerable, or if it affects very sensible parts.

Now, the degree in which the symptomatic fever is excited does not altogether depend upon the absolute quantity or violence of the inflammation, but in a great measure upon the degree of the local inflammatory action compared with the natural power and action of the part affected. Then, again, parts in which the action is naturally low are extremely painful when inflamed, and the system sympathises greatly with them. Hence, the constitution is very much affected when tendons, bones, or ligaments are the parts inflamed.

Severe inflammation of a large joint, every one knows, is apt to excite the most alarming symptoms, and even fatal derangement of the system; and when very sensible parts are inflamed, as, for instance, the eye, the symptomatic fever is generally more considerable than it would be were it to arise from an equal quantity and degree of inflammation in a less sensitive organ.

In common parts, such as muscles, cellular membrane, skin, etc, the symptoms will be acute, the pulse strong and full, and the more so if the inflammation be near the heart, but perhaps not so quick as when the part is far from it; the stomach will sympathise less, and the blood will be pushed farther into the small vessels. But, on the other hand, if the inflammation be in tendinous, ligamentous, or bony parts, the symptoms will be less acute, the stomach will sympathise more, the pulse will not be so full, but perhaps quicker, there will be more irritability, and the blood, not being propelled so well into the small vessels, will forsake the skin.

It seems to be a material circumstance whether the inflammation be situated far from or near the heart; for the symptoms are more violent, the constitution more affected, and the power of recovery less when the part inflamed is far from the source of the circulation than when near it, even where the parts are similar both in texture and use.

Should the heart or lung3 be inflamed either immediately or secondarily by sympathy, the disease has more violent effects upon the constitution than the same quantity of inflammation would, if the part affected were not a vital one, or one with which the vital parts did not sympathise. If the part be such as the vital ones readily sympathise with, then the sympathetic action of the latter will affect the constitution, as in inflammation of the urinary organs. In such cases the pulse is much quicker than if the inflammation were in a common part, such as muscles, cellular tissue, and skin.

We may, therefore, set down the ordinary symptoms of inflammatory fever, occurring in consequence of local inflammation in common parts, and in a healthy habit, as follows: - The pulse is frequent, full, and strong, all the secretions are diminished, the patient is vigilant and restless, the skin is hot and dry, the urine is high-coloured, an oppressive thirst is present, with general disturbance of the nervous system, loss of appetite, and, in some cases, unconsciousness.

Now allow me to observe here, that inflammation of small extent, particularly if not affecting organs of great importance in the economy, frequently commence, run their course, and terminate, without the action of the heart being in the least implicated. In Dr. Hunter's language, "the constitution does not sympathise with this minor degree of inflammation." Hence, since the action of the heart is not increased except when a considerable extent of inflammation exists, or, I would add, a more limited inflammation of highly important and sensible organs, the increased action of the heart cannot be regarded as a necessary constituent of inflammation. Consequently, no argument in favour of an increased action of the heart, or of the larger vessels, as causes of inflammation, drawn from extensive inflammations in which the heart is affected secondarily, can apply to those which are circumscribed and small, and during the whole course of which the heart may not beat even once oftener in a minute than it did before the local disease existed.