A Treatise on Fever

by Southwood Smith

II. Pathology of the Fluids in Fever.

The pathology of the solids in fever, derived from inspection of the fatal cases after death, has already acquired, as we have seen, a high degree of perfection. The pathology of the fluids is scarcely at all known, and the difficulty of arriving at exact and certain results is great. Why the investigation of the morbid changes that take place in the fluids should be a much more arduous task than that of tracing the changes produced in the structure of the organs, is too obvious to need to be pointed out; but those only who have actually engaged in researches of this nature can form a just conception of the number of repetitions that are requisite of the same analysis, of the care required in conducting each, and consequently, of the labour and time it is necessary to devote to the investigation, before satisfactory results can be obtained. The analysis of the animal fluids in their healthy state is far from being perfect; yet their composition in the state of health must be ascertained, as far as it can be ascertained, as a preliminary step: and, in order to discover the morbid changes that take place in the blood, in the urine, in the products of respiration, and in those of transpiration, and still further to determine the nature and extent of such changes in the different types and stages of fever, it is obviously necessary to examine the respective fluids and gases in a great number of cases, and to vary the experiments in a great variety of modes. Experiments of this kind, on an extensive scale, have been undertaken by my friend Mr. Cooper; and, when this work was commenced, they had already advanced so far that there appeared to be a prospect that, before its completion, they would be sufficiently matured to justify us in laying the results before the reader. And that deviations from the state of health, and some of them of great importance, do take place in these fluids, and especially in the blood and the urine, is ascertained. What they are, with what degree of constancy they occur, how far they are respectively connected with the cerebral, the thoracic, the abdominal, and the mixed affections, with different degrees of intensity in these affections, and with different stages of their progress, we hope, at no distant period, to be able to lay fully before the public.

In the mean time, it is of some importance to bear in mind the true place which the results of such experiments, be those results what they may, and be they established with all the clearness and certainty that can be desired, must always hold. Changes in the fluids can only be second in the series of morbid events; they can never hold the first place in that series; they can never be primary antecedents or first causes, but merely sequents or effects. To assign the reason of what must be so obvious to every one who is acquainted with the elements of physiology, would be entirely out of place here, because it would suppose the reader to be wholly ignorant of the functions of the animal economy. Our knowledge of the pathology of fever can never be complete, until we know the morbid changes that take place in the fluids as perfectly as we are acquainted with the alterations of structure that are produced in the solids, and we ought, therefore, to spare no labour to render our knowledge of the former as exact and certain as it is of the latter. But, as far as we can at present see, when this is accomplished, we shall have acquired little that is of practical utility. There is but slight, if there be any ground to hope that, when the humoral pathology shall have arrived at the greatest possible degree of perfection, it will furnish us with any additional means of preventing, curing, or even mitigating the severity of the disease. With that disorder of the system over which we have some control, with those morbid actions which we possess some means of subduing or changing, we are already well acquainted. In our knowledge of the invariable tendency there is to the production of certain changes in the structure of certain organs; in our knowledge of the vascular action by which those alterations are effected, we may be said, in a practical point of view, to be already in possession of the most important part of knowledge which we can ever hope to acquire, unless, indeed, we may indulge the expectation, of which it would be truly melancholy to be deprived, that we may discover a more sure and effectual mode of preventing these organic changes, or of restoring to a sound state the organs that may become diseased. It is this part of the pathology of fever alone that can afford a clear and steady light to conduct us to the safe and effectual treatment of the malady. Every step we take without this invaluable guide must be taken in the dark, and will be, therefore, not only likely to be false, but very likely to be fatal. When, on the contrary, we undertake the management of fever under the direction of this faithful guide, in every measure we venture to adopt we, at least, know at what we aim: we propose to ourselves a definite object which we endeavour to accomplish by an instrumentality with the powers of which we are in some degree acquainted: we may not succeed, but we fail because we want the means to do what we clearly see requires to be done: if we do not arrest the progress of the disease, at least we do not add to its strength by the adoption of violent and desperate expedients, because we feel called upon to do something, yet know not what to attempt; we do not destroy, if we cannot save. The physician, enlightened by the pathology of the disease, who prescribes for a patient in fever, is like a skilful surgeon, who is guided in the performance of a difficult and delicate operation by a knowledge of anatomy so intimate, that every touch of his scalpel exposes a tissue with which he is acquainted, and discloses the site of a vessel with which he is familiar; the object aimed at by the operation may not be obtained, but, at least, the cause of its failure is not that the operator wounds a structure which he ought to have avoided, or opens an artery, of the situation and distribution of which he is ignorant. On the contrary, the physician who prescribes for a patient in fever, without knowing the pathology of the disease, is like a Charlatan, who plunges his instrument boldly into the chest or the abdomen, without knowing where it goes or caring what it wounds; it may possibly open a tumour and let out the disease, but it is more likely to pierce some vital organ and to let out life.