that property of matter, or body, by which it excludes all other bodies from the place which itself possesses; and as it would be absurd to suppose that two bodies could possess one and the same place at the same time, it follows, that the fittest bodies are equally solid with the hardest. See Metaphysics, no. 44. 173. &c.

Among geometricians, the solidity of a body denotes the quantity or space contained in it, and is called also its solid content.

The solidity of a cube, prism, cylinder, or parallelopiped, is had by multiplying its basis into its height. The solidity of a pyramid or cone is had by multi-

tiplying either the whole base into a third part of the height, or the whole height into a third part of the base.