The possibility of “spontaneous combustion” occurring in bodies during life has been mentioned in the earlier writings on medical jurisprudence, and cases have been recorded in which it has been alleged to have taken place. Up to the present time no undoubted case of “spontaneous combustion” during life has been seen. On the other hand, the possibility of its occurrence is contra-indicated by the following facts: that the human body must consist of 75 per cent. of its weight of water, to be compatible with life, and that a dead body steeped in methylated spirit for many months or even years will never be consumed, if set on fire, in the rapid and complete manner alleged as occurring in cases of so-called “spontaneous combustion.” A case is recorded by Beatson (_B. M. J._, vol. i., 1886, p. 295) of a man, subject to foul eructations from the stomach, who got out of bed during the night and struck a match to see the time; while blowing out the light his breath took fire, producing an explosive noise sufficiently loud to awaken his wife. Such cases are very rare. It is a fact that by the action of certain micro-organisms upon organic matter inflammable gases are produced. That such an occurrence is possible, in the dead human body, is supported by cases recorded by Gull (_Med. Times and Gazette_, 1885) and Reynolds (_Med. Chron._, 1891). In Gull‘s case inflammable gases escaped through punctures made into the abdomen, and they burned spontaneously on contact with the air. In Reynold‘s case no flames were seen, but extensive and deep marks of burning were present, especially on the trunk and thighs. It has been suggested that the habitual use of alcohol in excess during life renders the tissues of the body more inflammable, but the matter is not yet decided. Tissues steeped in alcohol are not rendered more inflammable. Dr. Ogston, who cautiously avoids committing himself to the belief in “spontaneous combustion,” yet thinks that the subject of _preternatural combustibility_ in certain conditions of the body may perhaps, to say the least of it, be set down as one still _sub judice_. “There is no evidence to justify the use of the word ‘spontaneous,’ but there can be no doubt that an extraordinarily high degree of combustibility occurs in rare instances, to which the term _preternatural_ combustibility would more correctly apply” (J. Dixon Mann). Burns due to X-Rays Over-exposure to the action of X-rays produces burns of a peculiar character, and in cases of unprotected skin exposed to the action of the rays in those who are constantly working with them, forms of dermatitis have arisen which are intractable and tend to become epitheliomatous in character.