Volume, Capacity, Density

Since the limit of the extensity of a body can be internally pre-inscribed in its matter, the previously proposed criterion for distinguishing 'Volume' from 'Capacity'--source of delimitation as internal vs. external--is inadequate, though it still follows that any externally imposed circumscription is a capacity.  So, an alternative characterization of that contrast is that Capacity, but not Volume, connotes a heterogeneity of contour and content, such that content is conceivable as variable with respect to contour.  Thus, the standard definition of 'density', which conceives the 'mass' of a body as variable with respect to a cubic unit, entails Capacity, properly, not Volume.  In contrast, 'density', as conceived as how 'tightly packed' the parts of a body are, i. e. conceived in terms of its internal relation of Repulsion to Attraction, maintains the actual integrity of Volume.  Now, clearly illustrating the distinction between Volume and Capacity is the contrast between solids, on the one hand, and liquids and gases, on the other, respectively.  Hence, the standard definition of 'density' is more appropriate to liquids and gases than to solids.