Depending on the granularity, this powder can have an abrasive feel, similar to pumice powder, and has a low density as a result of its high porosity. The typical chemical composition of oven-dried diatomaceous earth is 80 to 90% silica, with 2 to 4% alumina (attributed mostly to clay minerals) and 0.5 to 2% iron oxide. Diatomaceous earth consists of fossilized remains of diatoms, a type of hard-shelled algae.
A Pacinian corpuscle is a type of touch receptor located in the skin. It is classed as a mechanoreceptor, meaning it is part of the group of sensory receptors that respond to touch and pressure.lthough there are similarities between the two, a Pacinian corpuscle is not as discriminatory as the type of fine-touch mechanoreceptor present in the fingertips, known as Meissner's corpuscle. This type of sensory receptor lies closer to the surface of the skin and adapts only moderately fast.
bundle, early 13c., probably from a Low German word (cf. Middle Dutch pac, pack bundle, Middle Low German pak, Middle Flemish pac, attested from late 12c.), originally a term of wool traders in Flanders; or possibly from Old Norse pakki. All are of unknown origin. Italian pacco is a Dutch loan word; French pacque probably is from Flemish. Meaning set of persons (usually of a low character) is c.1300, older than sense of group of hunting animals (early 15c.). Extended to collective sets of playing cards (1590s), floating ice (1791), cigarettes (1924), and submarines (1943).