10. Intermissions, or the _intermitting_ and remitting states of fever, are common to all the states of fever which have been mentioned. But they occur most distinctly and universally in those which partake of the bilious diathesis. They have been ascribed to the reproduction of bile, to the recurrence of debility, and to the influence of the heavenly bodies upon the system. None of these hypotheses has explained the recurrence of fever, where the bile has not been in fault, where debility is uniform, and where the paroxysms of fever do not accord with the revolutions of any part of the solar system. I have endeavoured to account for the recurrence of the paroxysm of fever, in common with all other periodical diseases, by means of a natural or adventitious association of motions. Dr. Percival has glanced at this law of animal matter; and Dr. Darwin has explained by it, in the most ingenious manner, many natural and morbid actions in the human body. 11. There is a state of fever in which the morbid action of the blood-vessels is so feeble as scarcely to be perceptible. Like the hectic state of fever, it seldom affects the brain, nerves, muscles, or alimentary canal. It is known in the southern states of America by the name of _inward_ fevers. The English physicians formerly described it by the name of febricula. These eleven states of fever may be considered as _primary_ in their nature. All the states which remain to be enumerated belong to some one of them, or they are compounds of two, three, or more of them. Even these primary states of fever seldom appear in the simple form in which they have been described. They often blend their symptoms; and sometimes all the states appear at different times in the course of a fever. This departure from a uniformity in the character of fevers must be sought for in the changes of the weather, in the casual application of fresh irritants, or in the operation of the remedies which have been employed to cure them. To the first class of the states of fever belong the sweating, the fainting, the burning, and the cold and chilly states of fever. 12. The _sweating_ state of fever occurs in the plague, in the yellow fever, in the small-pox, the pleurisy, the rheumatism, and in the hectic and intermitting states of fever. Profuse sweats appeared every other day in the autumnal fever of 1795 in Philadelphia, without any other symptom of an intermittent. The English sweating sickness was nothing but a symptom of the plague. The sweats in all these cases are the effects of morbid and excessive action, concentrated in the capillary vessels. 13. The _fainting_ state of fever accompanies the plague, the yellow fever, the small-pox, and some states of pleurisy. It is the effect of great depression; hence it occurs most frequently in the beginning of those states of fever.