Earwax in the canal. Jaw movement assists this process by dislodging debris attached to the walls of the ear canal, increasing the likelihood of its expulsion. The lubrication provided by cerumen prevents desiccation of the skin within the ear canal. The lubricative properties arise from the high lipid content of the sebum produced by the sebaceous glands. In wet-type cerumen, these lipids include cholesterol, squalene, and many long-chain fatty acids and alcohols. While studies conducted up until the 1960s found little evidence supporting antibacterial activity for cerumen, more recent studies have found that cerumen has a bactericidal effect on some strains
Substance theory Substance theory Substance theory, or substance–attribute theory, is an ontological theory about objecthood, positing that a "substance" is distinct from its properties. A "thing-in-itself" is a property-bearer that must be distinguished from the properties it bears. "Substance" is a key concept in ontology and metaphysics, which may be classified into monist, dualist, or pluralist varieties according to how many substances or individuals are said to populate, furnish, or exist in the world. According to monistic views, there is only one substance. Stoicism and Spinoza, for example, hold monistic views, that pneuma or God, respectively, is the one substance in the