FORCE.
A FORCE is a Power which initiates or accelerates aggregative motion, while it resists or retards separative motion, in two or more particles of ponderable matter (and possibly also of the ethereal medium).
All particles possess the Power of attracting one another — in other words, of setting up mutually aggregative motion — unless prevented by some other Power of an opposite nature. Thus a body suspended freely in the air is attracted towards the earth by the Force (or aggregative Power) known as Gravitation. A piece of sugar, held close over a cup of tea, attracts into itself the water of the tea-cup, by the Force (or aggregative Power) known as Capillarity. A spoon left in tea grounds or a foot planted on the moist sand similarly attracts the neighbouring drops. A piece of iron or coal exposed to free oxygen (each at a certain fixed temperature) attracts the particles of oxygen by the Force known as Chemical Affinity. In every case there must be an absence of counteracting Energies (or separative Powers) sufficient to prevent the union of the particles, as will be shown hereafter: but for the present it will be enough to notice that every particle attracts every other particle in some one of various ways, unless prevented by other Powers.
Not only, however, do all particles thus attract one another, but they also resist all attempts to separate them from one another. A weight suspended in the air falls to the ground: but it also resists any attempt to remove it from the ground, which can only be done by the employment of a proportionate Energy (or separative Power). The water which the sugar has absorbed can only be drawn from it by the Energy of suction. The oxygen with which the iron has united can only be driven off by the Energy of heat: while the carbonic anhydride and water which resulted from the burning of the coal yield only as a rule to the separative Energy of light or electricity. In every case the Force which brought two or more particles together in the first instance keeps them united ever after, and must be neutralised by an equal Power of an opposite description before they can be disjoined.