So that the irritative ideas of the apparent motions of objects, the irritative battements of sounds, and the movements of our bowels and glands compose a great circle of irritative tribes of motion: and when one considerable part of this circle of motions becomes interrupted, the whole proceeds in confusion, as described in Section XVII. 1. 7. on Catenation of Motions.

Great surprise at awaking. And total forgetfulness of what passed in reverie. 3. No suspension of volition in reverie. 4. Sensitive motions continue, and are consistent. 5. Irritative motions continue, but are not succeeded by sensation. 6. Volition necessary for the perception of feeble impressions. 7. Associated motions continue. 8. Nerves of sense are irritable in sleep, but not in reverie. 9.

As in these constitutions more than the natural quantities of sensitive motions are produced by the increased quantity of sensation existing in the habit, it follows, that the irritative motions will be performed in some degree with less energy, owing to the great expenditure of sensorial power on the sensitive ones.

Verbal contention is, of course, commoner among the poor and the vulgar than in the class of well- bred people living at their ease, but I doubt whether the lower ranks of society find personal association much more difficult than the refined minority above them. High cultivation may help to self-command, but it multiplies the chances of irritative contact.

When we are employed with great sensation of pleasure, or with great efforts of volition, in the pursuit of some interesting train of ideas, we cease to be conscious of our existence, are inattentive to time and place, and do not distinguish this train of sensitive and voluntary ideas from the irritative ones excited by the presence of external objects, though our organs of sense are furnished with their accustomed stimuli, till at length this interesting train of ideas becomes exhausted, or the appulses of external objects are applied with unusual violence, and we return with surprise, or with regret, into the common track of life.

The sharks seemed to find the presence of the forlorn groveller in the mud unendurable when it stained the water red, though apparently indifferent to its presence as long, as it remained quiescent, which facts lend confirmation to the popular opinion that the fluid possesses a caustic-like principle violently irritative to the skin.

The associate trains or circles of motions continue; but their catenations with some of the irritative motions are disordered, or inverted, or dissevered. Sleep from satiety of hunger. From rocking children. From uniform sounds. 2. Intoxication from common food after fatigue and inanition. 3. From wine or of opium. Chilness after meals. Vertigo.

This subject is very intricate. It would appear, that by certain morbid actions of the salivary glands of the mad dog, a peculiar kind of saliva is produced; which being instilled into a wound of another animal stimulates the cutaneous or mucous glands into morbid actions, but which are ineffectual in respect to the production of a similar contagious material; but the salivary glands by irritative sympathy are thrown into similar action, and produce an infectious saliva similar to that instilled into the wound.

There are many motions of the body, belonging to the irritative class, which might by a hasty observer be mistaken for associated ones; as the peristaltic motion of the stomach and intestines, and the contractions of the heart and arteries, might be supposed to be associated with the irritative motions of their nerves of sense, rather than to be excited by the irritation of their muscular fibres by the distention, acrimony, or momentum of the blood.

One of these, like acute rheumatism, is closely related to, and probably caused by, the attack of acute infections of milder character, falling upon less favorable soil. The other is of a vaguer type and is due, probably, to the accumulation of poisonous waste-products in the tissues, setting up irritative and even inflammatory changes in nerve, muscle, and joint.