Pyrectica. Fevers. Proximate cause. ORDER I. burgh Medical Transactions *; in which last the author, following up the hint thrown out by Boerhaave in the aphorism just quoted, endeavours to show how well the two ideas of lentor and spasm are disposed to amalgamate in forming the proximate cause of fever; the spasm consisting of an universal muscular tension, and the lentor being united according to the nature of the case with inflammation, acrimony, or both; and hence often producing what he denominates an alternate NISUS and RE III. Spasm of the extreme vessels. Cullen's modification in the formation of a new system. Its high merit. System explaned. NISUS. The materials, however, were now becoming too unwieldy; and the wheels of the machine were clogged by the very forces that were designed to increase its motion. Dr. Cullen was well aware of this, and boldly ventured upon a new attempt for the purpose of simplifying and facilitating its progress. As his basis he took the hypothesis of Stahl as modified and improved by Hoffman : and on this basis erected his stately and elaborate structure, so well known to the medical world, full of ingenuity and daring genius, and which, if it be at this moment crumbling into decay, certainly is not falling prostrate before any fabric of more substantial materials or more elegant architecture. Dr. Cullen has been accused of the same want of ingenuousness towards Hoffman, as Hoffman is chargeable with towards Stahl ; and of having introduced his system to the public with little or no acknowledgement of the sources from which he has drawn. But surely no one can bring forward such an accusation, who has read with any degree of attention the preface to his Practice of Physic, in which he gives a full account of Dr. Hoffman's system in his own words, and pays complete homage to his merits. According to the more elaborated principles of the Cullenian system, the human body is a congeries of organs regulated by the laws not of inanimate matter, but of life, and superintended by a mobile and conservative power or energy, seated in the brain, but distinct from * Vol. iv. Art. xxin, and Vol v. Part. 11. Art. XLVIIL Pyrectica. cause. III. Spasm sels. the mind or soul; acting wisely but necessarily, for the ORDER I. general health; correcting deviations, and supplying de- Fevers. fects, not from a knowledge and choice of the means, Proximate but by a pre-established relation between the changes produced, and the motions required for the restoration of the exof health; and operating therefore, through the medium treme vesof the moving fibres, upon whose healthy or unhealthy state depends the health or unhealthiness of the general frame which fibres he regarded, with Stahl, as simple nerves, the muscular filaments being nothing more than their extremities, and by no means possessed of an independent vis insita. Close assobrain, stomach, and vessels. ciation of extreme The brain therefore, upon this hypothesis, is the primum mobile, but it closely associates in its action with the heart, the stomach, and the extreme vessels. The force of the heart gives extension to the arteries, and the growth of the body depends upon such extension in conjunction with the nutritious fluid furnished by the brain, and deposited by the nerves in the interstices of their own fibres; the matter of which fibres is a solid of a peculiar kind, whose parts are united by chemical attraction. All nervous power commences in the encephalon; it "consists in a motion beginning in the brain and propagated from thence into the moving fibres, in which a contraction is to be produced. The power by which this motion is propagated, we name", says Dr. Cullen, "the ENERGY of the brain; and we therefore consider Energy of every modification of the motions produced, as modifi- the brain cations of that energy." He further lays it down as a law of the economy, that the energy of the brain is al- Alternately ternately excited and collapsed, since every fibrous contraction is succeeded by a relaxation: whence spasms and convulsions are motus abnormes, and consist in an irregularity of such alternation. But we must distinguish in this system between the energy of the brain and the vital fluid it sends forth by the nerves; for while the former rises and sinks alternately, the latter remains per Mat. Med. Part. 11. Chap. VIII. 349. what. excited and collapsed. Nervous fluid not a secretion. ORDER I. Pyrectica. Fevers. Proximate cause. III. Spasm of the extreme vessels. accounted for. manently the same. It is not a secretion, but an inherent principle, never exhausted, and that never needs renewal *. This hypothesis, in its various ramifications, influenced every part of his theory of medicine, and consequently laid a foundation for his doctrine of fever. The proxiFever hence mate cause of fever was, in his opinion, a collapse or declination of the energy of the brain produced by the application of certain sedative powers, as contagion, miasm, cold, and fear, which constitute the remote This diminished energy extends its influence over the whole system, and occasions an universal debility; but chiefly over the extreme vessels, on which it induces a spasm; and in this spasm the cold fit is supposed to consist. Cullen's proximate cause of fever. Energy of the brain restored by debility. Division of the par oxysm into three stages, not including that of sweat. causes. "Such, however," to adopt the words of Dr. Cullen himself, "is the nature of the animal economy, that this debility proves an indirect stimulus to the sanguiferous system; whence by the intervention of the cold stage, and spasms connected with it, the action of the heart and larger arteries is increased, and continues so till it has had the effect of restoring the energy of the brain, of extending this energy to the extreme vessels, of restoring therefore their action, and thereby especially overcoming the spasm affecting them; upon the removing of which, the excretion of sweat, and other marks of the relaxation, of the excretories, take place."† This relaxed or perspiratory section of the paroxysm, however, is not regarded by Dr. Cullen as a part of the disease, but as the prelude to returning health. Yet the fit still consists of three stages; the first of debility or diminished energy, the second of spasm, and the third of heat. And though Dr. Cullen had some doubts whether the remote causes of fever might not produce the well as spasm as the atony of the nervous system, yet he inclined to ascribe the second stage to the operation of the first, as he did most decidedly the third to that Mat. Med. Part. II. Chap. v. p. 223. + Pract. of Phys. § XLVI. of the second: and thus to regard the whole as a regular ORDER I. series of actions, employed by the vis medicatrix naturæ for the recovery of health. Pyrectica. Fevers. Proximate cause. III. Spasm of the ex treme ves fails. That fever in its commencement or earliest stage is characterized by debility of the living fibre, or, more closely in the words of Dr. Cullen, by diminished energy sels. of the brain, extending directly or indirectly to the vo- System how luntary muscles and capillaries, and producing the signa far correct. prodroma of Professor Frank*, cannot for a moment be doubted by any one who accurately watches its phænomena. And thus far the Cullenian hypothesis is unquestionable correct; as it appears to be also in supposing the cold stage to be the foundation of the hot, and of the excretion of sweat by which the hot stage is succeeded; the entire series forming Frank's signa constitutiva. But it fails in the two following important points, with- In what reout noticing a few others of smaller consequence. The spects it spasm on the minute vessels produced by debility takes the lead in the general assault; and, though it forms only a link in the remedial process, is the most formidable enemy to be subdued; and hence all that follows Febrile parin the paroxysm is an effort of the system to overcome accounted this spasm. The effort at length proves successful: the debility yields to returning strength; the spasm is conquered, and the war should seem to be over. But this is not the fact: the war continues notwithstanding; there is nothing more than a hollow truce; debility and spasm take the field again, and other battles remain to be fought. There is nothing in this hypothesis to account for a return of debility and spasm, after they have been subdued; nor to show why spasm should ever in the first instance be a result of debility. "In this system", says Dr. Parr, "the production of spasm by debility, is an isolated fact without a support; and the introduction of the vires medicatrices naturæ, is the interposition of a divinity in an epic, when no probable resource is at hand." * De Curand. Hom. Morb. Tom. I. p. 3. 8vo. Mannh. 1792. oxysms not for after the first. ORDER I. Pyrectica. Fevers. Proximate The next striking defect that must occur to the atten-、 tive reader is, that debility is here made a cause of strength; the weakened action of the first stage giving rise to the increased action and re-excited energy that making de- restore the system to a balance of health and here again we stand in need of the interposition of some present divinity to accomplish such an effort by such means. cause. Error in bility a cause of strength. IV. Accu exhausted or doctrine of Brown. IV. It is not, therefore, to be wondered at that this mulated or system, with all its ingenuity and masterly combination, excitability. should not have proved satisfactory to every one. In Excitability, reality, it did not for many years prove satisfactory to one in the celebrated school in which it was first every propounded. And hence, under the plastic hands of Dr. Brown arose another hypothesis, of which I shall proceed to give a very brief outline, together with the modi- . fication it received under the finishing strokes of Dr. Darwin. Rise of Dr. Brown and his hypothesis. Its simplicity and plausibility. Hypothesis explained. Dr. Brown, who was at first a teacher of the classics: at Edinburgh, and a translator of inaugural theses into Latin, commenced the study of medicine about the mid-. dle of life, by a permission to attend the medical schools gratuitously. He was at first strongly attached to Dr. Cullen and Dr. Cullen's system; but an altercation ensued, and he felt an equal animosity towards both. A, new and opposite system, if so it may be called, was in, consequence manufactured and publicly propounded in a variety of ways. It had great simplicity of principle, and some plausibility of feature; it attracted the curiousby its novelty, the indolent by its facility, and every one by the boldness of its speculations. It circulated widely, and soon acquired popularity abroad as well as at home. Man, according to Dr. Brown, is an organized machine, endowed with a principle of excitability, or predisposition to excitement, by means of a great variety of stimuli both external and internal, some of which are perpetually acting upon the machine; and hence the excitement which constitutes the life of the machine is Excitability maintained. Excitability, therefore, is the nervous energy of Dr. Cullen; and, like that, is constantly varying in its accumulated |