Two characteristic appearances--redness and vesication--are present in burns inflicted during life when the surface of the body is not charred and the tissues destroyed. The redness affects the surface and entire substance of the true skin, which is dotted by the deep red openings of the sudoriferous and sebaceous ducts. This appearance cannot be produced after death. Blisters are formed by a temperature somewhat less than that of boiling water. Vesication, according to Orfila, is characteristic of a burn inflicted during life, and the late Sir Robert Christison found that in burns caused before and after death the vesicles in the former contained serum, the latter air. In anasarcous subjects, however, serous blisters may be formed, especially if the heat employed be not too severe. A case is recorded by Taylor in which vesicles containing bloody serum were formed on the body of a man who had just been drowned and who had been put into a hot bath. Ante-mortem vesicles in which vital reaction has taken place present the following characteristics: (_a_) They contain serous fluid in which albumin and chlorides can be detected. (_b_) An inflammatory red bounding line round the circumference. (_c_) Inflammatory redness of the base, and the papillæ of the skin. (_d_) The presence of pus, which would indicate that the person had lived at least thirty-six hours after the burn had taken place. In burns produced after death, the surface and substance of the skin is of a dull white colour, dotted with grey openings of the sudoriferous and sebaceous ducts, and the subcutaneous tissues are uninjected. Vesicles produced by burns may have to be distinguished from the phlyctænæ, the result of advanced putrefaction. The latter possesses none of the characteristics of the former. If a vesicle present the following characteristics it may be accepted as a post-mortem origin without doubt: if it be small and its contents scanty, if the fluid it contain be free from albumin and chlorides, if it contain air, and if there be no signs of inflammatory reaction. =Was the burning homicidal, suicidal, or accidental?=--No general rules for guidance can be here laid down. In most cases the conditions under which the body is found will point less to suicide than to homicide or accident. In cases of murder, the body is often burnt in the attempt to destroy all traces of the crime. It must, however, be borne in mind that intense heat applied to the body may give rise to a wound on the surface like that caused by a cutting instrument. Casper mentions such a case, in which a wound was found over the liver, due to the application of intense heat to the body. The conjunction of robbery will greatly assist in helping to solve the difficulty. It may be very confidently stated that to dispose of a body by burning is no easy matter. Preternatural Combustibility