Minerals are essential substances naturally found in both animal and vegetable goods.

Cholesterol is an essential substance produced by the body.

"Trust is the essential substance of an alliance," cautioned a West German official.

It has for years had a strict policy against publishing manuscripts whose "essential substance" has been published elsewhere.

Gene therapy would deliver the needed gene to a person's cells, which would then begin producing the essential substance.

A substance so essential to the existence of City Earth that its chemical name was rarely used.

Water and vitamins are two of the most essential substances available to us.

Vitamins are a group of substances essential for normal cell function, growth and development.

It's as if some essential substance had been drained from the objects, leaving only ghostly shells.

For example, he argued against the concept of platonic ideal forms, and that something's essential substance and existence were one and the same.