2p13def.md (422B)
1 When any given bodies of the same or different magnitude are compelled by other 2 bodies to remain in contact, or if they be moved at the same or different rates 3 of speed, so that their mutual movements should preserve among themselves a 4 certain fixed relation, we say that such bodies are in union, and that together 5 they compose one body or individual, which is distinguished from other bodies by 6 the fact of this union. 7 8