Page:On the various forces of nature and their relations to each other.djvu/60

56 if I put two pieces of coke in some part of the solution (the coke ought first to be washed very clean, and dried), you will find to-morrow that we shall have a beautiful crystallisation over the coke, making it exactly resemble a natural mineral.

Now, how curiously our ideas expand by watching these conditions of the attraction of cohesion!—how many new phenomena it gives us beyond those of the attraction of gravitation! See how it gives us great strength. The things we deal with in building up the structures on the earth are of strength (we use iron, stone, and other things of great strength); and only think that all those structures you have about you—think of the "Great Eastern," if you please, which is of such size and power as to be almost more than man can manage—are the result of this power of cohesion and attraction.

I have here a body in which I believe you will see a change taking place in its condition of cohesion at the moment it is made. It is at first yellow, it then becomes a fine crimson red. Just watch when I pour these two liquids together—both colourless as water. [The