You perceive from the drawing (fig. 6) that there is a great difference between the two pillars of the plantar arch. The hinder pillar is comparatively short, and narrow, and descends suddenly, almost in a vertical direction, from the ankle, to the ground; and it is composed of only one bone--the heel-bone--which is jointed directly with the astragalus: whereas the fore pillar is longer and broader, is composed of several bones jointed together, and slopes much more gradually to the ground. There is, therefore, far less elasticity in the hinder part of the foot than in the fore part. Hence, when we descend from a height upon the ground, we always alight upon the balls of the toes, and thus gain the advantage which the several bones and joints afford in breaking the shock. If, after going up stairs this evening, you take the trouble to come down again, you will find that you alight upon each stair on the balls of the toes and experience no inconvenience, however quickly the descent is made. But, if you change the mode of proceeding, and descend upon the heels, the feeling will be by no means agreeable; and the various organs of the body, being disturbed from their accustomed repose, will raise such remonstrances against your infringement upon nature’s ways, that you will scarcely be able to continue the experiment. Proportionately more distressing is the sensation caused by jumping from a chair upon the heels. Indeed, this is not done altogether without risk; and the trial of it is scarcely to be recommended to persons who have attained to that sober period of life at which we are willing to concede that, in some things, nature is wiser than ourselves. Only a short time since I saw a gentleman, who, in jumping down some steps into a back yard, accidentally came upon his heels, and jarred one hip so severely that he was confined to his sofa for several days in consequence. But, you may say, “in walking we do place the heel upon the ground first and experience no inconvenience.” True, because the force with which the foot descends in walking is very slight; and the weight is directed upon the heel, obliquely, in such a manner as to bring the toes very quickly to the ground, and really to throw nearly the whole force in that direction. Moreover, you may observe that when we walk, the weight of the body is partly sustained by the fore part of the one foot till the whole of the other foot is on the ground. I will, however, revert to the disposition of the feet in walking and running presently.