The structure, deformation, friction and wear of an electrographite have been investigated. A large proportion of this material consists of nearly spherical carbon black particles, about 2000 Å in diameter, which have an `onion-like' structure with graphitic layers oriented parallel to the surface. The interlocking between the edges of adjacent graphitic regions is sufficient to destroy the plastic properties which are characteristic of true graphite. At the microscopic scale, the material is extremely hard (> 1000 V.P.N.), but the presence of porosity makes it macroscopically weak (22 V.P.N.). It has an apparent Young's modulus which is of the order of 10¹⁰ c.g.s. units, but which depends on the previous history; indentation experiments using a ½ in. steel ball show that it will recover almost completely from the large deformation caused by a load of 100 kg. There is no sharp yield point; failure is by brittle fracture.The coefficient of friction μ has been measured in a crossed-cylinders apparatus; it is shown that the variation of μ with load is consistent with the supposition that the deformation at the contact is elastic. After repeated rubbing, soft films (6 V.P.N.) of wear debris are formed on the rubbed surfaces. These films are accompanied by a reduction of about 30% in μ. Electron micrographs of such films show that they contain carbon black particles and also their degradation products. Electron diffraction shows that the films sometimes contain graphitic planes oriented nearly parallel to the surface. The ability of a film to exhibit orientation depends on the relative proportions of carbon black particles and of the free layer planes formed by processes of degradation during wear.