rendered languid in the mental functions, and become stupified in the same manner by the too great application of the mind to the study of wisdom, the body must unavoidably pine away, the animal spirits being consum’d, which are the only instruments of rightly performing both material and spiritual operations[2].” These are indeed observations highly just. For he who is not ignorant what a multitude of nerves there are in the animal system, who is sensible that there is no function that can be performed without them, will easily apprehend that by the fatigue of the medulla a languor may be brought upon all the nerves, so that the several functions may be weakened, and the strength of the body may, without its being exercised, be totally exhausted. It is universally known that there are books compos’d without any strength of genius, which appear quite insipid and unaffecting to the reader, and only tire the eyes; but those that are compos’d with an exquisite force of ideas, and with an exact connexion of thought, elevate the soul, and fatigue it with the very pleasure, which, the more compleat, lasting, and frequent it is, breaks the man the more[3]. MALEBRANCHE was seized with dreadful palpitations in reading DESCARTES’S Man; and there is still living at Paris a professor of rhetoric, who fainted away whilst he was perusing some of the sublime passages of HOMER[4]. The head itself, and the nerves, and the stomach which is fuller of nerves than any other part, first suffer for the errors of the mind. An eminent person, who had impair’d his health by too intense an application to study, was immediately seiz’d by a terrible vertigo, if he happen’d to listen attentively to a person telling a story. He likewise complained, that nothing could give him greater uneasiness than his attempting to recall the memory of any thing, for then he was put to the greatest pain imaginable, and sometimes seiz’d with a fainting fit, attended with a sense of extreme lassitude. Nor could he desist from his effort after he had once begun it, though he labour’d ever so much for that purpose; but was under a necessity of proceeding as he had begun, till he fainted away[5]. The illustrious VIRIDET, formerly my fellow-citizen, knew a woman who, whenever she us’d any application of mind, was seiz’d with a severe fit of the colic[6]. And a late author speaks of a man who never either thought intensely, or experienc’d any lively sensation, or was put in a passion, but his whole arm immediately swell’d up[7]. Both of which cases may be explained by the defect of the nerves alone, and the action of the mind upon the nerves.