Everything which the animal body contains is derived, directly or indirectly, from vegetable foods; and the mineral or ash it leaves, when burned, must have come from the soil through the plant. When the animal dies, its body sooner or later returns to the soil. So we have another circle in which the earthy matter of animals and plants moves. It ascends from the soil to the plant, then to the animal, and back again to mother earth, so that it is really "dust to dust."

The plant does not absorb all mineral matters, but selects the rarer and more precious materials from the soil, and such as are held in solution by water. Phosphoric acid, lime, magnesia, and saline matter, of which common salt is a representative, are the principal substances chosen. The animal eating the vegetable, these substances enter its stomach, and are dissolved and enter the blood. The vessels provided for the purpose select the required material, and, like ships in commerce, sail away on the blood rivers to their destined havens. The saline portion is carried to the blood and tissues. The phosphate of lime goes to the bones, and phosphate of potash to the muscles. After a time the animal, partly as it wastes and finally when it dies, returns to the soil all that the plant took from it. New plants receive it, and it goes the rounds again.

So, over and over again, as the modeller fashions his clay, plant and animal are formed out of the same material. Is all senseless matter to be constantly working, and are we intelligent beings to idle away a precious but limited existence? One should learn from this always to work for a definite purpose.

How lovely is the plant in its position of bond-servant of man! How willing and interesting! It serves till death, yet rises again rejoicing as ever, when spring returns, to renew its destined toil.

The least alteration in the natural constitution of things would insure the extinction of animal and vegetable life.