Nor does too intense an application produce only slight and transient convulsions of the muscles; it likewise renews and generates the most dreadful nervous disorders. GALEN[13] mentions a grammarian, who was seized with a fit of the epilepsy, whenever he meditated profoundly, or taught with vehemence. I myself have seen instances of it. And the illustrious VAN SWIETEN laments the case of youths of the brightest hopes, who have been seiz’d with a dreadful and incurable epilepsy, upon being compell’d by severe masters to apply to their studies with scarce any intervals of relaxation. HOFFMAN[14] makes mention of a young man, who, as often as he weary’d out his memory and his genius by attentive study, was seiz’d with a momentary epilepsy, a palpitation of the heart, and a trance; but when he remitted of his assiduity, was always tolerably well. This the celebrated PETRARCH likewise unhappily experienc’d, being seiz’d with an epilepsy through his great application to study, to which he was immoderately attach’d. In a public promotion, one of the candidates for literary honour, after having pursu’d his studies with the moil arduous application both day and night, through a too great attention to his oration, that he might be able to say it accurately by heart, was suddenly seiz’d with a catalepsy and fell down[15]. The labour of the mind not only produces nervous disorders, but, by means of the nerves, gives rise to other complaints. An eminent mathematician, who was troubled with an hereditary gout, and had always liv’d soberly and chastely, hasten’d a paroxysm by applying a long time to the solution of a difficult problem[16]. And the case of the chevalier DE PERNAY is very extraordinary. After four months of the closest study imaginable, and without any previous disorder, his beard fell first, then his eye-lashes, then his eye-brows, then the hair of his head, and finally all the hairs of his body[17]. Did this proceed from the great relaxation of the roots, from which the hairs grow; or from the want of nutrition? Certain it is, that an intense application of mind relaxes the whole corporeal frame, and prevents all nutrition for two reasons; for this is the effect of thought, not upon all, but upon most constitutions, that it accelerates the pulse, and produces a fever, which, by dissolving the nourishing jelly of the fluids, occasions paleness, leanness, consumption, and a sort of wasting of the nerves; on the other hand, the cessation of the action of the nerves, is capable of producing it. Nor does it less cease in the whole body, whilst it is obstructed by application of mind, than when it is stopped by a swelling or a ligature in any part. We should not be too inquisitive in prying into causes; and many circumstances relating to nervous disorders will for ever remain unknown: but if any one should be curious to know how the too great tension of the nerves is hurtful, I will briefly give him my sense of the matter.