Heavier substances tend to fall to the bottom while lighter ones float to the top. These lighter things consume us. We consume them and are never satisfied.
substance |ˈsəbstəns|
noun
the real physical matter of which a person or thing consists and which has a tangible, solid presence : proteins compose much of the actual substance of the body.
• the quality of having a solid basis in reality or fact : the claim has no substance.
• the quality of being dependable or stable : some were inclined to knock her for her lack of substance.
the quality of being important, valid, or significant : he had yet to accomplish anything of substance.
• the most important or essential part of something; the real or essential meaning : the substance of the treaty.
