Action of both mind and body ought to be so continued as to serve as relaxation to each other. The mind of a man, still more of a child, is incapable of long perseverance in mental exertion. This is a generally acknowledged truth, to which I shall add one more to the same purpose, which is less known. Young men, and those who are not advanced in years, if healthy and of warm constitutions, are never very greatly inclined to mental exertion till their bodies are to a certain degree fatigued, I do not say wholly exhausted. Till this fatigue is produced, their body has a preponderance over the mind, and in this case it is a truly natural want, which cannot easily be silenced. Each muscle requires exertion, and the whole machine strives to employ its powers; this is vulgarly called to have no sit-still flesh. If the fatigue be once brought on, the call for bodily exertion is stilled; the mind is no longer disturbed by it, and all its labours are facilitated. Our common mode of education pays no regard to this: youths appear in school to be strengthened by sleep and food, and too frequently, alas! thrown into an unnatural heat and commotion. How is it possible to fix the attention under such circumstances? The body requires action; if this be not allowed, it will obtain it in silence; it will act upon the passions, and, above all, the fiery temperament of youth will influence the imagination. Thus attention slumbers. We are barbarous when we attempt to awaken it with the rod; we require from innocent children what is unnatural; we inflict pain on the body to prevent its action; yet activity was bestowed on it by its creator; yet nature renovates this activity every night; the mind is soon carried away by the whirlwind of corporal energies, and lost in the realm of chimeras. To facilitate the contemplation of them, I shall just repeat the desirable parallel between the qualities of the body and mind:--Health of body--serenity of mind--hardiness--manliness of sentiment--strength and address--presence of mind and courage--activity of body--activity of mind--excellence of form--mental beauty--acuteness of the senses--strength of understanding. MEDICUS. * * * * *