suitable piece of iron from the loadstone, if only it touch the iron; otherwise it does not snatch it away, though in closest proximity. For magnetick pieces of iron within the orbe of virtue, or near a loadstone, do not rush together with a greater endeavour[175] than the iron and the magnet; but joined they are united more strongly and, as it were, cemented together, though the substance remain the same with the same forces acting. * * * * * CHAP. XVIII. An armed Loadstone does not endow an excited piece of Iron with greater vigour _than an unarmed_. Suppose there are two pieces of iron, one of * which has been excited by an armed loadstone, the other by one unarmed; and let there be applied to one of them another piece of iron of a weight just proportional to its strength, it is manifest that the remaining one in like manner raises the same and no more. Magnetick versoria also touched by an armed loadstone turn with the same velocity and constancy towards the poles of the earth as those magnetized by the same loadstone unarmed. * * * * * {88} CHAP. XIX. Union with an armed Loadstone is stronger; _hence greater weights are raised; but the_ coition is not stronger[176], but _generally weaker_. An armed magnet raises a greater weight, as is manifest to all; but a piece of iron moves towards a stone at an equal, or rather greater, distance when it * is bare, without an iron cap. This must be tried with two pieces of iron of the same weight and figure at an equal distance, or with one and the same versorium, the test being made first with an armed, then with an unarmed loadstone, at equal distances. * * * * * [Illustration] CHAP. XX. * An armed Loadstone raises an armed Loadstone, _which also attracts a third; which likewise_ happens, though the virtue in the first _be somewhat small_. Magnets armed cohære firmly when duly joined, and accord into one; and though the first be rather weak, yet the second one adhæres to it not only by the strength of the first, but of the second, which mutually give helping hands; also to the second a third often adheres and in the case of robust stones, a fourth to the third. * * * * * {89} CHAP. XXI. * If Paper or any other Medium be interposed, an armed loadstone raises no more than an _unarmed one_. Observation has shown above that an armed loadstone does not attract at a greater distance than an unarmed one; yet raises iron in greater quantity, if it is joined to and made continuous with the iron. But if Paper be placed between, that intimate cohæsion of the metal is hindered, nor are the metals cemented together at the same time by the operation of the magnet. * * * * * [Illustration] CHAP. XXII. *