But there are certain distinct and different principles which the body requires should be furnished to it, out of food. You stand there very firmly on the ground, and you look jolly and substantial enough. I should think from your appearance you have been in no way stinted in the matter of supplies. I estimate, at a guess, that your substantial body would weigh, some one hundred and fifty pounds, if placed in the scales. Now what do you think the greater part of those one hundred and fifty pounds is composed of. Bones? Not exactly, you are too soft for that. Flesh? There seems plenty of flesh, but the flesh is not the most abundant element. Brains? I am afraid they are less than the flesh. No. You will wonder indeed when I tell you that three-quarters of that firm and well-knit frame are nothing else but water. If I were to take your body and dry it until all its water was gone, there would remain behind nothing but thirty-seven pounds of dry mummy-substance, in the place of the original one hundred and fifty pounds; one hundred and thirteen pounds of water would have steamed away. You will see then that water must be furnished in fair quantity, with or in the food. You have heard, I do not doubt, many horrible and sad things which have happened when people have been kept a long time without water. Thanks to the bounty of Providence, this privation is, however, one that very rarely occurs. But now, supposing that we have steamed away the one hundred and thirteen pounds of water, and that there are left behind thirty-seven pounds of dry substance, what does that substance consist of? It still contains several distinct things, which have had entirely distinct offices to perform in the living frame. First, you know, there is that flesh, which makes so comely a show. Now, we shall be able to find out how much there really is of flesh. Of dry flesh-substance, including a little skin and jelly, there are seventeen pounds, and that is the working part of the frame. It is by its means the ton-weight can be lifted one mile high in a single day, and that all the moving and acting, of whatever kind, are effected. Remember, then, that the acting part of the living body is flesh-substance, and that of that flesh-substance there are not more than seventeen pounds in a full-grown man.