Zoonomia; Or, the Laws of Organic Life, Vol. II

by Erasmus Darwin

Hence when the stomach is torpid, as in sickness, this torpor sometimes only affects the absorbent vessels of it; and then the absorbents of the cellular membrane and the skin only act with increased energy by reverse sympathy. If the torpor affects the muscular fibres of the stomach, those of the heart and arteries act by direct sympathy with it, and a weak pulse is produced, as in the exhibition of digitalis, but without increase of heat. But if the torpor also affects the glands of the stomach, the cutaneous and pulmonary glands act with greater energy by their reverse sympathy with those of the stomach, and of the heart and arteries; and great heat is produced along with increased perspiration both from the skin and lungs.

[3]. There is some difficulty in explaining, why the actions of the extensive system of capillary glands, which exist on every other membrane and cell in the body for the purpose of secreting mucus and perspirable matter, should so generally act by reverse sympathy with those of the stomach and upper part of the intestines. It was shewn in Class [IV. 1. 1. 6]. that when the stomach was filled with solid and fluid aliment, the absorbents of the cellular membrane, and of the bladder, and of the skin acted with less energy; as the fluids they were used to absorb and transmit into the circulation, were now less wanted; and that hence by habit a reverse sympathy obtained between these branches of the absorbents of the alimentary canal, and those of the other parts of the body.

Now, as at this time less fluid was absorbed by the cutaneous and cellular lymphatics, it would happen, that less would be secreted by their correspondent secerning vessels, or capillary glands; and that hence by habit, these secerning vessels would acquire a reverse sympathy of action with the secerning vessels of the alimentary canal.

Thus when the absorption of the tears by the puncta lacrymalia is much increased by the stimulus of snuff; or of an affecting idea, on the nasal dusts, as explained in Sect. XVI. 8. 2. a great increase of the secretion of tears from the lacrymal glands is produced by the direct sympathy of the action of these glands with those of their correspondent absorbents; and that though in this case they are placed at so great a distance from each other.

[4]. A difficult question here occurs; why does it happen, that in fevers with weak pulse the contractions of the heart and arteries become at the same time more frequent; which also sometimes occurs in chlorosis, and in some hysteric and hypochondriac diseases, and in some insanities; yet at other times the weak pulse becomes at the same time slow, as in the exhibition of digitalis, and in paresis irritativa, described in Class [I. 2. 1. 2]. which may be termed a fever with slow pulse? this frequency of pulse can not depend on heat, because it sometimes exists without heat, as towards the end of some fevers with debility.

Now as apoplexies, which are sometimes ascribed to fulness of blood, are attended with slow pulse; and as in animals dying in the slaughter house from deficiency of blood the pulse becomes frequent in extreme; may not the frequency of pulse in fevers with arterial debility be in general owing to paucity of blood? as explained in Sect. XXXII. 2. 3. and its slowness in paresis irritativa be caused by the debility being accompanied with due quantity of blood? or may not the former circumstance sometimes depend on a concomitant affection of the brain approaching to sleep? or to the unusual facility of the passage of the blood through the pulmonary and aortal capillaries? in which circumstance the heart may completely empty itself at each pulsation, though its contractions may be weak. While the latter depends on the difficulty of the passage of the blood through the pulmonary or aortal capillaries, as in the cold fits of intermittents, and in some palpitations of the heart, and in some kinds of hæmoptoe? in these cases the increased resistance prevents the heart from emptying itself, and in consequence a new diastole sooner occurs, and thus the number of pulsations becomes greater in a given time.

[5]. In respect to the sympathies of action, which produce or constitute fever with debility, the system may be divided into certain provinces, which are assentient or opposite to each other. First, the lacteals or absorbent vessels of the stomach, and upper part of the intestines; secondly, the lymphatics or all the other branches of the absorbent vessels, which arise from the skin, mucous membranes, cellular membranes, and the various glands. These two divisions act by reverse sympathy with each other in the hot fits of fever with debility, though by direct sympathy in the cold ones. The third division consists of the secerning vessels of the stomach and upper intestines; and the fourth of the secerning vessels of all the other parts of the body, as the capillary glands of the skin, lungs, and cellular membrane, and the various other glands belonging to the sanguiferous system. Many of these frequently, but the capillaries always, act by reverse sympathy with those of the third division above mentioned in the hot fits of fever with debility, though by direct sympathy with them in the cold fits. Fifthly, the muscular fibres of the stomach, and upper intestines; and sixthly, the muscular fibres of the heart and arteries. The actions of these two last divisions of moving fibres act by direct sympathy with each other, both in the cold and hot fits of fevers with debility.

The efficient cause of those apparent sympathies in fevers with weak pulse may be thus understood. In the cold paroxysm of fever with weak pulse the part first affected I believe to be the stomach, and that it has become torpid by previous violent exertion, as by swallowing contagious matter mixed with saliva, and not by defect of stimulus, as from cold or hunger. The actions of this important organ, which sympathizes with almost every part of the body, being thus much diminished or nearly destroyed, the sensorial power of association is not excited; which in health contributes to move the heart and arteries, and all the rest of the system; whence an universal torpor occurs.

When the hot fit approaches, the stomach in fevers with strong pulse regains its activity by the accumulation of the sensorial power of either irritation, if it was the part first affected, or of association if it was affected in sympathy with some other torpid part, as the spleen or liver; which accumulation is produced during its torpor. At the same time all the other parts of the system acquire greater energy of action by the accumulation of the sensorial power of association, which was produced, during their inactivity in the cold fit.

But in fevers with weak pulse the stomach, whose sensorial power of irritation had been previously exhausted by violent action, acquires no such quick accumulation of sensorial power, but remains in a state of torpor after the hot fit commences. The heart and arteries remain also in a state of torpor, because there continues to be no excitement of their power of association owing to the torpid motions of the stomach; but hence it happens, that there exists at this time a great accumulation of the power of association in the less active fibres of the heart and arteries; which, as it is not excited and expended by them, increases the associability of the next link of the associated chain of motions, which consists of the capillaries or other glands; and that in so great a degree as to actuate them with unnatural energy, and thus to produce a perpetual hot fit of fever. Because the associability of the capillaries is so much increased by the accumulation of this power, owing to the lessened activity of the heart and arteries, as to over-balance the lessened excitement of it by the weaker movements of the heart and arteries.