The elements are not proper substances in Aristotelian theory or the modern sense of the word.

We need to have a clear implementation plan for fulfilling these commitments so that the new legal structures available are given proper substance.

He described the membrane that is situated between the corneal "proper substance" and the endothelial layer of the cornea.

Wonder not then, what God for you saw good If I refuse not, but convert, as you To proper substance.

These ultimately leave the trabecular sheaths, and terminate in the proper substance of the spleen in small tufts or pencils of minute arterioles, which open into the interstices of the reticulum formed by the branched sustentacular cells.