So close is the connexion between mind and body, that we cannot well conceive the operations of the one independent of some correspondence with the other. For as the senses are incapable of conveying the materials of thought to the soul, without the motion both of their own fibres and those of the brain, so, whilst the mind revolves these cogitations, the organs of the brain are more or less stimulated to act, stretch’d, and have oscillatory motions excited in them. The mind agitates the machine; and these are the labours of the medullary part, which, being so tender, does not suffer the less by these motions; and every man easily feels that in himself, which the strongest arms experience after the most violent exercise. For which of you, that has been addicted to a studious life, has not often found, after intense thought, that the innermost part of the brain has been affected by a troublesome heat, and intense pain, such as the muscles feel when fatigu’d with long labour? Nor does the medullary part of the brain suffer alone, but the very eyes themselves can perceive the force of the thinking soul, extended beyond the brain: for whilst we look upon a man that meditates seriously, all the muscles of his face appear stretched, nay sometimes convuls’d. Nor does the brain, the medulla of which is the source of the nerves, suffer alone, but they themselves are hurt; and PLATO has admirably shewn, in the masculine style in which he so greatly excell’d, how much the exercise of the mind prejudices the body. “Quando anima, inquit, corpore admodum potentior est, exultatque in eo atque effertur, totum ipsum intrinsecus quatiens languoribus implet. Quando etiam ad dicendum, investigandumque, collectis in unum viribus, vehementer incumbit, liquefacit prorsus corpus, & labefactat; denique cum ad dicendum, differendumque privatim & publice ambitiosa quadam concertatione contendit, inflammat corpus atque resolvit. Tam arcta enim lege consortii, sic RAMAZZINI, fœderantur anima & corpus ut omnia tam bona quam mala unius in alterum vicissim corrivent, ac veluti, ex corporis nimia exercitatione, anima ad mentis functiones languescit, ac torpet, sic ob nimiam animæ contentionem, circa sapientiæ studium, corpus marcescat necesse est, absumptis nempe spiritibus, communi scilicet instrumento ad materiales & spirituales operationes rite obeundas.” “As the mind, says he, is far more powerful than the body, and exults and is elate therein, it affects it inwardly, and fills it entirely with languor; and when, by gathering together its strength, it applies earnestly to learning and to the investigating of things, it quite dissolves and unhinges the body: finally, when with an ambitious emulation it exerts itself to speak and harangue both in private and public, it inflames the body and relaxes it. For, as RAMAZZINI observes, the soul and body are united by so firm a league, that all the advantages and disadvantages of the one must affect the other; and as the soul is