The raw material--condemned meat, offal and other organs of the animal recovered from the slaughter-house which possess no edible value--is charged into a steam-jacketed horizontal extractor fitted with stirring gear. When condemned carcasses are to be treated there is no need to carry out preliminary deboning; it is merely necessary to reduce the material to rough pieces for convenience of handling. It will be observed that the steam is not brought into contact with the mass, but is circulated through the jacket as in the dry vacuum process. The solvent is introduced in the first instance in the form of vapour, being passed through boxes of special construction, to pass finally into the extractor. The contents of the latter being in a condition of constant agitation as a result of the manipulation of the stirring gear, the benzine vapour is able to permeate the mass. The heat radiated from the steam circulating through the jacket converts the moisture present in the material into vapour and with which the solvent comes into contact. Vaporization of the moisture causes the solvent itself to condense to a certain degree, and in the liquid form it dissolves out the grease. The process is continued until the bulk of the moisture has been eliminated, when the grease and solvent are withdrawn. When the grease has been fully extracted down to a limit which will result in a dry meat-meal, containing about 1 per cent. of grease, the benzine is steamed off in the usual manner. The benzine itself is recovered because it is only permitted to work in a closed circuit, and, after fulfilling its purpose, is passed to a still to be cleaned and purified, after which it is again passed to the extractor to repeat the cycle of operation.