[9]. This doctrine of reverse sympathy enables us to account for that difficult problem, why in continued fevers the increased action of the cutaneous, cellular, and pulmonary capillaries proceeds without interruption or return of cold fit; though perhaps with some exacerbations and remissions; and that during a quarter, or half, or three quarters, or a whole lunation; while at the same time the pulsations of the heart and arteries are weaker than natural.

To this should be added the direct sympathy, which exists between the peristaltic motions of the fibres of the stomach, and the pulsations of the heart. And that the stomach has become torpid by the too great stimulus of some poisonous or contagious matter; and this very intricate idea of continued fever with feeble pulse is reduced to curious simplicity.

The direct sympathy of the stomach and heart and arteries not only appears from the stronger and slower pulse of persons exhausted by fatigue, after they have drank a glass of wine, and eaten a few mouthfuls; but appears also from the exhibition of large doses of digitalis; when the patient labours under great and incessant efforts to vomit, at the same time that the actions of the absorbent system are known to be much increased by the hasty absorption of the serous fluid in anasarca, the pulsations of the heart become slow and intermittent to an alarming degree. See Class [IV. 2. 1. 17]. and [18].

[10]. It would assist us much in the knowledge and cure of fevers, if we could always determine, which part of the system was primarily affected; and whether the torpor of it was from previous excess or defect of stimulus; which the industry of future observers must discover. Thus if the stomach be affected primarily, and that by previous excess of stimulus, as when certain quantities of opium, or wine, or blue vitriol, or arsenic, are swallowed, it is some time in recovering the quantity of sensorial power previously exhausted by excess of stimulus, before any accumulation of it can occur. But if it be affected with torpor secondarily, by sympathy with some distant part; as with the torpid capillaries of the skin, that is by defective excitement of the sensorial power of association; or if it be affected by defect of stimulus of food or of heat; it sooner acquires so much accumulation of sensorial power, as to be enabled to accommodate itself to its lessened stimulus by increase of its irritability.

Thus in the hemicrania the torpor generally commences in a diseased tooth, and the membranes about the temple, and also those of the stomach become torpid by direct synchronous sympathy; and pain of the head, and sickness supervene; but no fever or quickness of pulse. In this case the torpor of the stomach is owing to defect of the sensorial power of association, which is caused by the too feeble actions of the membranes surrounding the diseased tooth, and thus the train of sympathy ceases here without affecting the motions of the heart and arteries; but where contagious matter is swallowed into the stomach, the stomach after a time becomes torpid from exhaustion of the sensorial power of irritation, and the heart and arteries act feebly from defect of the excitement of the power of association. In the former case the torpor of the stomach is conquered by accumulation of the power of association in one or two whole days; in the latter it recovers by accumulation of the power of irritation in three or four weeks.

In intermittent fevers the stomach is generally I believe affected secondarily by sympathy with the torpid cutaneous capillaries, or with some internal torpid viscus, and on this account an accumulation of sensorial power arises in a few hours sufficient to restore the natural irritability of this organ; and hence the hot fit succeeds, and the fever intermits. Or if this accumulation of sensorial power becomes excessive and permanent, the continued fever with strong pulse is produced, or febris irritativa.

In continued fevers the stomach is frequently I suppose affected with torpor by previous excess of stimulus, and consequent exhaustion of sensorial power, as when contagious matter is swallowed with the saliva, and it is then much slower in producing an accumulation of sensorial power sufficient to restore its healthy irritability; which is a frequent cause of continued fever with weak pulse or febris inirritativa. Which consists, after the cold fit is over, in a more frequent and more feeble action of the heart and arteries, owing to their direct sympathy with the muscular fibres of the torpid stomach; together with an increased action of the capillaries, glands, and absorbents of the skin, and cellular membrane, owing to their reverse sympathy with the torpid capillaries, glands, and absorbents of the stomach, or with those of the heart and arteries.

Or in more accurate language. 1. The febris inirritativa, or fever with weak pulse, commences with torpor of the stomach, occasioned by previous exhaustion of sensorial power of irritation by the stimulus of contagious matter swallowed with the saliva. 2. The whole system becomes torpid from defect of the excitement or the sensorial power of association owing to the too feeble actions of the stomach, this is the cold fit. 3. The whole system, except the stomach with the upper intestines, and the heart and arteries, falls into increased action, or orgasm, owing to accumulation of sensorial power of association during their previous torpor, this is the hot fit. 4. The stomach and upper intestines have not acquired their natural quantity of sensorial power of irritation, which was previously exhausted by violent action in consequence of the stimulus of contagious matter, and the heart and arteries remain torpid from deficient excitement of the sensorial power of association owing to the too feeble actions of the stomach. 5. The accumulation of sensorial power of association in consequence of the torpor of the heart and arteries occasions a perpetual orgasm, or increased action of the capillaries.

[11]. From hence it may be deducted first, that when the torpor of the stomach first occurs, either as a primary effect, or as a secondary link of some associate train or circle of motions, a general torpor of the system sometimes accompanies it, which constitutes the cold fit of fever; at other times no such general torpor occurs, as during the operation of a weak emetic, or during sea-sickness.

Secondly. After a time it generally happens, that a torpor of the stomach ceases, and its actions are renewed with increase of vigour by accumulation of sensorial power during its quiescence; as after the operation of a weak emetic, or at the intervals of sea-sickness, or after the paroxysm of an intermittent fever.