" What wonder then, if fields and regions here Breathe forth elixir pure, and rivers ran Potable gold, when with one virtuous touch Th' arch-chemic Sun, so far from us remote, Produces, with terrestrial humour mix'd Here in the dark, so many precious things. Of colour glorious, and effects so rare ? "
Every one knows that common substance called clay, which is so easily mixed into a paste with water. But every one does not consider perhaps what an important part in agriculture and industry this familiar substance performs.
All soils that are of value for the production of vegetables contain clay. The principal element of this substance—alumina—is necessary to the development of plants; and its presence is necessary to retain the humidity of soil that is indispensable to vegetable life.
To indicate the importance of clay in the industrial world it is only necessary to say that tiles, bricks, pottery, from the coarsest kind to the finest
