Lucretious poem, De Rerum Natura has the following:
Again, why see we among objects some
Of heavier weight, but of no bulkier size?
Indeed, if in a ball of wool there be
As much of body as in lump of lead,
The two should weigh alike, since body tends
To load things downward, while the void abides,
By contrary nature, the imponderable.
Therefore, an object just as large but lighter
Declares infallibly its more of void
This appears to be a qualitative understanding of mass in Antique Physics; given that if 'a ball of wool there be as much body as in a lump of lead' then 'the two should weigh alike'; whilst still tied up with the notion of Aristotelian mass which moves downward.
Further, 'an object just as large but lighter declares infallibly its more of void'; expresses a qualitative understanding of density, in that a lighter object just has less mass and more void.
At least this is my interpretation - is there any corrobative contemporary writings that support this interpretation?
Finally, is void the correct translation of the term Lucretious's poem, given that the Parmenidian Void doesn't express space as such; but is of pure absence; and that Lucretian Physics developed out of the Parmenidian critique. What are the two respective terms in the original Greek?