Honey extraction abrading the surface of the wax with moving chains or bristles or hot knives. This, while messy, makes the process easier than doing this task manually. Some beekeepers will also harvest (before uncapping the honey) the propolis, a resinous material bees gather to glue the frames together; propolis is used for its medicinal properties. Once uncapped, the frames are then placed in a honey extractor, which spins them so that most of the honey is removed by centrifugal force. Care must be taken to ensure that all frames are loaded correctly, as the comb is angled slightly upwards to prevent
Mental substance Mental substance Mental substance is the idea held by dualists and idealists, that minds are made-up of non-physical substance. This substance is often referred to as consciousness. This is opposed to the materialists, who hold that what we normally think of as mental substance is ultimately physical matter (i.e., brains). Descartes, who was most famous for the assertion "I think therefore I am", has had a lot of influence on the mind–body problem. He describes his theory of mental substance (which he calls res cogitans distinguishing it from the "res extensa") in the "Second Meditation" (II.8) and in "Principia Philosophiae"