A Treatise on Fever

by Southwood Smith

The importance of making this analysis has been felt by every person who has directed his attention to this subject from the remotest antiquity down to the present time. That it is not as easy to be made as the necessity of it is plainly to be perceived is abundantly attested by the want of success which has hitherto attended the efforts to perform it of the acutest minds, and the acutest minds, the pride and boast of our science have applied themselves to the task. Notwithstanding their labours however, the analysis made by Hippocrates has been received through succeeding ages with little variation, and continues to be received even in modern times with only slight modification. And yet that reflecting men of every age have not been satisfied with resolving all the essential phenomena of fever into heat, although they have all consented to designate the disease by some term expressive of that property,[^[17]] is attested by proofs no less striking than instructive. We are informed by Van Swieten, that Boerhaave collected with much labour from a great variety of authors all the symptoms which they had observed in different fevers: that from these he threw out such as did not appear in all fevers, and that finding himself obliged to exclude one after another, he was at length greatly surprised to find the catalogue so short; it being ultimately reduced to three; namely shivering, frequent pulse, heat.

This is a sufficient and an interesting proof that this illustrious physician saw the importance of making the analysis in question; it shews also, that his ingenuity suggested probably the best mode of conducting it which a philosopher sitting in his study could devise; and the only proper mode of conducting it the circumstances of his age and country did not place within his reach. Accordingly his success did not equal his labour: for out of the three phenomena which he fixes upon as those that are common to all the varieties of the disease there is not one which is invariably found in any type of it; while in innumerable cases the combination of the three is not found. Shivering does not occur in some of the worst forms of the malady; and where it does, it is confined to the commencement of the attack, or to that of its exacerbations. The pulse, instead of being always more frequent than natural, in some of the most formidable aspects assumed by the disease, has been observed to be as low as forty or even thirty in the minute, and, from the beginning to the termination of the attack, the heat in some cases is below the natural standard, as it generally is in the commencement of the cold stage.

To the catalogue of Boerhaave, Cullen makes the following additions:—“languor, lassitude and other signs of debility, together with derangement of the functions, particularly a want of vigor in the limbs without any primary local affection.” This extension of the catalogue adds in no respect to the excellence of the generalization. It has all the vices which a definition can possess. The characters are not present in all cases; the very opposite are strikingly prominent in many, while the last, “without any primary local affection,” has so direct a tendency to mislead the mind, and positively to prevent it from observing the real phenomena of the disease, that it may well be questioned, whether the introduction of this single phrase into the definition of fever, has not been the occasion of far more practical mischief than has been compensated by any good that has been accomplished, or ever can be accomplished by all the rest of the nosology.

In the last attempt to improve the definition of fever with which I am acquainted, Dr. Wilson Philip says, “If we lay aside Dr. Cullen’s term pyrexia, (which it must be borne in mind is precisely Boerhaave’s brief catalogue) we shall considerably lessen the difficulty of giving such a definition of idiopathic fevers as shall apply to all cases. They may be defined as follows. Languor, lassitude, and other signs of debility, followed by a frequent pulse, and increased heat, without any primary local affection.”[^[18]] Inasmuch as this definition contains fewer words than that proposed by Cullen, it may be liable to fewer objections, but it is less faulty only because it is shorter.

This total failure of men, all of them of unquestionable acuteness, and some of them of splendid genius, in their attempts to discover the common phenomena of fever, affords a strong presumption that they have not pursued their object in the right path. Without doubt, before it is possible to succeed in any scientific investigation, it is necessary to form a distinct conception of the object of inquiry. Fever is not an entity, not a being possessing a peculiar nature; and the object of investigating it, is not to discover in what such nature consists, or what it is that constitutes its essence: but fever is a series of events, and the object of inquiry is to discover what the events are; what the events are that invariably concur in the series; and in what order they constantly succeed each other. When we have discovered this, we have ascertained all that we can ever know of what is termed the nature of fever, as it is this, and only this, that we can ever know of any object or process. Every natural object consists either of one single substance, or of several substances united; and our knowledge of that object is complete when we have ascertained what that single substance is; or what all the separate substances are that combine to form it. Every natural process consists of a number of events, and our knowledge of that process is complete when we have ascertained the events themselves, the order of their succession, and the events to which they give occasion. We can make no real progress in knowledge unless we keep steadily in view the kind of information which it is possible to acquire, and which it is to our purpose to seek; and dispossess our minds of the phantoms which have so long enthralled and abused them.

In relation to our present subject then, the first object of enquiry is, what are the events which invariably concur in fever?

Where shall we look for the events? Not in the symptoms. Symptoms are not events: they are only indications of events: symptoms depend upon states of organs: they are the external and visible signs of internal, and, for the most part, as long as life continues, invisible conditions. It is then to the state of the organs that we must look for the events of which we are in search.

Are there any states of any organs that always exist in fever? Are the states constant? Are the organs affected constant; and can both be ascertained? If this can be truly answered in the affirmative; if it can be proved that there are certain conditions of certain organs which invariably exist in fever, in every type, in every degree, in every stage of it, we shall have arrived at a satisfactory conclusion relative to the first part of our inquiry.

The evidence is as complete as observation during life and inspection after death can make it, that a morbid change does take place in a certain number of organs in every case of fever, from the most trivial intermittent to the most alarming continued fever, from the mildest plague to the most malignant typhus: that at the two extremes of this scale, and at all the intermediate gradations of it, there are certain organs which are always affected, and that the affection in all is similar.

The identity of the organs is inferred from the indications they give of disordered function during life: the identity of the affection is inferred from the similarity of morbid appearances which they exhibit on examination after death.