Who are the farmer’s servants? Not the Irish, nor the coolies, but Geology and Chemistry, the quarry of the air, the water of the brook, the lightning of the cloud, the castings of the worm, the plough of the frost. Long before he was born, the sun of ages decomposed the rocks, mellowed his land, soaked it with light and heat, covered it with vegetable film, then with forests, and accumulated the sphagnum whose decays made the peat of his meadow. Science has shown the great circles in which nature works; the manner in which marine plants balance the marine animals, as the land plants supply the oxygen which the animals consume, and the animals the carbon which the plants absorb. These activities are incessant. Nature works on a method of _all for each and each for all_. The strain that is made on one point bears on every arch and foundation of the structure. There is a perfect solidarity. You cannot detach an atom from its holdings, or strip off from it the electricity, gravitation, chemic affinity, or the relation to light and heat, and leave the atom bare. No, it brings with it its universal ties. Nature, like a cautious testator, ties up her estate so as not to bestow it all on one generation, but has a forelooking tenderness and equal regard to the next and the next, and the fourth, and the fortieth age. There lie the inexhaustible magazines. The eternal rocks, as we call them, have held their oxygen or lime undiminished, entire, as it was. No particle of oxygen can rust or wear, but has the same energy as on the first morning. The good rocks, those patient waiters, say to him: ‘We have the sacred power as we received it. We have not failed of our trust, and now--when in our immense day the hour is at last struck--take the gas we have hoarded; mingle it with water; and let it be free to grow in plants and animals, and obey the thought of man.’ The earth works for him; the earth is a machine which yields almost gratuitous service to every application of intellect. Every plant is a manufacturer of soil. In the stomach of the plant development begins. The tree can draw on the whole air, the whole earth, on all the rolling main. The plant is all suction-pipe,--imbibing from the ground by its root, from the air by its leaves, with all its might.