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system. But whether any of these sedative powers be alone the remote cause of fever, or if they only operate either as concurring with the operation of marsh or human effluvia, or as giving an opportunity to the operation of cold, are questions not to be positively answered: they may possibly of themselves produce fever ; but most frequently they operate as concurring in one or other of the ways above mentioned..
98. Having now mentioned the chief of the remote causes of fevers, it may be further observed, that these will arise more or less readily, according as miasmata and contagions are more or less prevailing and powerful, or as these are more or less favoured by the concurrence of cold and other sedative powers.
OF THE PROGNOSIS OF FEVERS.
99. As fevers (by 60), consist of both morbid and salutary motions and symptoms, the tendency of the disease to a happy or fatal issue, or the prognostic in fevers, has been established by marking the prevalence of the morbid or of the salutary symptoms; and it might be properly so established, if we could certainly distinguish between the one and the other of these kinds of symptoms : but the operation of the reaction, or salutary efforts of nature, in curing fevers, is still involved in so much obscurity, that I cannot explain the several symptoms of it so clearly as to apply them to the establishing prognostics; and this, I think, may be done better by marking the morbid symptoms which shew the tendency to death in fevers.
100. This plan of the prognostics in fevers must proceed upon our knowledge of the causes of death in general, and in feyers more particularly.
The causes of death, in general, are either direct or indirect.
The first are those which directly attack and destroy the vital principle, as lodged in the nervous system, or destroy the organization of the brain immediately necessary to the action of that principle.
The second or the indirect causes of death, are those which interrupt such functions as are necessary to the circulation of the blood, and thereby necessary to the due continuance and support of the vital principle.
101. Of these general causes, those which operate more particularly in fevers seem to be, first,
The violence of reaction ; which either, by repeated violent excitements, destroys the vital power itself; or, by its violence, destroys the organization of the brain necessary to the action of that power; or, by the same violence, destroys the organization of the parts more immediately neces, sary to the circulation of the blood. .
Secondly, The cause of death in fevers may be a poison, that is, a power capable of destroying the vital principle; and this poison may be either the miasma or contagion which was the remote cause of the fever, or it may be a putrid matter generated in the course of the fever. In both cases, the operation of such a power appears either as acting chiefly on the nervous system, inducing the symptoms of debility; or as acting upon the fluids of the body, inducing a putrescent state in them.
102. From all this it appears, that the symptoms shewing the tendency to death in fevers, may be discovered by their being either the symptoms
Of violent reaction ;
Or, of a strong tendency to putrefaction in the fluids.
And, upon this supposition, I proceed now to mark those symptoms more particularly.
103. The symptoms which denote the violence of reaction, are 1, The increased force, hardness, and frequency, of the pulse. 2, The increased heat of the body. 3, The symptoms which are the marks of a general inflammatory diathesis, and more especially of a particular determination to the brain, lungs, or other important viscera. 4, The symptoms which are the marks of the cause of violent reaction ; that is, of a strong stimulus applied, or of a strong spasm formed, the latter appearing in a considerable suppression of the excretions.
104. The symptoms which denote a great degree of debility, are, .
In thé ANIMAL FUNCTIONS: 1, The weakness of the voluntary motions ; 2, the irregularity of the voluntary motions, depending on their debility; 3, the weakness of sensation ; 4, the weakness and irregularity of the intellectual operations.
In the VITAL FUNCTIONS: 1, The weakness of the pulse; 2, the coldness or shrinking of the extremities; 3, the tendency to a deliquium animi in an erect posture; 4, the weakness of respiration.
In the NATURAL FUNCTIONS: 1, The weakness of the stomach, as appearing in anorexia, nausea, and vomiting ; 2, involuntary excretions, depending upon a palsy of the sphincters; 3; difficult deglutition, depending upon a palsy of the muscles of the fauces.
105. Lastly, The symptoms denoting the pretrescent state of the fluids, are,
1, With respect to the stomach; the loathing of animal food, nausea, and vomiting, great thirst, and a desire of acids.
2, With respect to the fluids: 1, The blood drawn out of the veins not coagulating as usual ; 2, hemorrhagy from different parts, without marks of increased impetus; 3, effusions under the skin or cuticle, forming petechiæ, maculæ, and vibices; 4, effusions of a yellow serum under the cuticle.
3, With respect to the state of the excretions ; fetid breath, frequent, loose, and fetid stools, highcoloured turbid urine, fetid sweats, and the fetor and livid colour of blistered places.
4, The cadaverous smell of the whole body. it
106. These several symptoms have very often, each of them singly, a share in determining the prognostic ; but more especially by their concurrence and combination with one anothor, particularly those of debility with those of putrescency.
107. On the subject of the prognostic, it is proper to observe, that many physicians have been of opinion, there is something in the nature of fe. vers which generally determines them to be of a certain duration; and therefore that their terminations, whether salutary or fatal, happen at certain periods of the disease rather than at others.