S. Austin Allibone, comp. Prose Quotations from Socrates to Macaulay. 1880.
Labour or exercise ferments the humours, casts them into their proper channels, throws off redundancies, and helps nature in those secret distributions without which the body cannot subsist in its vigour, nor the soul act with cheerfulness.
I might here mention the effects which this has upon all the faculties of the mind, by keeping the understanding clear, the imagination untroubled, and refining those spirits which are necessary for the proper exertion of our intellectual faculties, during the present laws of union between soul and body. It is to a neglect in this particular that we must ascribe the spleen which is so frequent in men of studious and sedentary tempers, as well as the vapours to which those of the other sex are so often subject.
There is no kind of exercise which I would so recommend to my readers of both sexes as this of riding, as there is none which so much conduces to health, and is every way accommodated to the body, according to the idea which I have given of it. Doctor Sydenham is very lavish in its praises; and if the English reader would see the mechanical effects of it described at length, he may find them in a book published not many years since, under the title of the Medicina Gymnastica.
Had not exercise been necessary, nature would not have given such an activity to the limbs, and such a pliancy to every part, as produces those compressions and extensions necessary to the preservation of such a system.