DEFINITION IV.
Thomas Salusbury translation
But I call that Body more grave absolutely than this, if that weigh more than this, without any respect had to the Masses.
And thus a great piece of Wood is said to weigh more than a little lump of Lead, though the Lead be in specie more heavy than the Wood. And the same is to be understood of the less grave in specie, and the less grave absolutely.
These Termes defined, I take from the Mechanicks two Principles: the first is, that