28:23 · The regular hexagon, a uniform, six-sided, geometrical design, is used in Western ideography in the contexts of chemistry and electricity and in engineering to represent a flow restriction. The substance benzene is a very important compound in aromatic organic chemistry, i.e. the field of chemistry working with compounds based upon carbon. Benzene is used as a dissolvant when producing pharmaceutical products. It is a poisonous and extremely flammable substance that is extracted from coal tar.
    Different models for the benzene molecule have long been designed to try to explain the chemical properties of benzene. It was the German Friedrich August Kekule von Stradonitz who, because of a dream he had in 1865, devised the best model to date, which happened to have the form . This has, since then, become a universally accepted model of the chemical structure of benzene.