OF THE GOVERNMENT OF THE PHYSICAL WORLD

All matter appears to exert force. The particles of the diamond cohere with so intense an energy, that it requires great mechanical power to separate them. The mountains seem inert, but they are constantly pressing downwards towards the centre of the earth. Water slumbering peacefully in the bosom of a lake, is exerting a pressure on the bottom and sides, and is in fact operating with a force similar to that which it manifests in rushing over the precipice. In the latter case, we perceive the force only because there is no counterbalancing resistance to arrest its action.

Farther, the forces of different substances act on each other, and produce important results. Oxygen acting on sulphur, in certain circumstances, combines with it and produces sulphuric acid, a highly corrosive liquid. Under the influence of heat, the same gas combines with carbon, and produces a gas destructive of animal life. If this reciprocal action of corporeal substances were indefinite and unlimited, the physical world, apparently, might lapse into confusion, chaos might come again, and the earth could afford no abiding place for animated beings. How is this result obviated? And by what means are order in the arrangements and regularity in the evolutions of matter preserved?

Each elementary substance manifests the tendency to undergo changes, and to act on other substances, only in certain ways and under certain conditions.