1. Superficial inflammation, characterised by redness without blistering. 2. Acute inflammation, the epidermis raised, forming vesicles containing serum. 3. Destruction of the superficial layers of the true skin. 4. Destruction of the true skin and subcutaneous cellular tissues. 5. The superficial and deep parts converted into a charred mass. 6. Entire carbonisation of the parts. (Dupuytren.) Post-mortem Appearances These will vary according to the extent of the injuries, the length of time the individual lived after receiving them, and the causative agent. =External Appearances.=--1. _Burns._--Radiant heat whitens the skin, flames blacken it, from deposit of carbonaceous material. The hair and clothing of the body are singed. Blisters may be present on various parts, and roasted patches of the skin or deeper parts may be present. The flame of an explosive, such as a mixture of coal gas and air, scorches and mummifies the skin. The skin is blackened by the explosion of gunpowder, and particles of the powder may be driven into it; similar results follow explosions in coal mines, but to a greater degree. Burns caused by red-hot solids or molten metals vary in appearance according to the length of time they have remained in contact with the surface: if short, there may be injury to the skin only, with blistering; if for a longer period, there will be roasting or charring of the part, and blisters may not be present. All stages of burns may be present. The uncovered parts of the body, as a rule, are more affected than the clothed, unless the clothes become ignited, when the converse would hold good. In cases where the clothes have been saturated with an inflammable oil like petroleum the burns are much more severe. 2. _Scalds._--The appearances produced and the severity of the result will vary directly with the boiling-point of the liquid. Boiling water and steam produce vesication; the hairs are not affected. If the steam be superheated, blistering may be absent, and the skin appear sodden and devoid of elasticity. If the person survive the injuries for some days, the skin will present appearances of reaction. After exposure to great heat the bodies of the victims are usually contorted, with the limbs flexed and the arms fixed in a defensive attitude--the “pugilistic attitude.” This condition is due to _heat rigidity_. =Internal Appearances.=--The brain is shrunk, usually without any alteration in form, the lungs also shrunk, and the larynx, trachea, and bronchi may contain carbonaceous material; their membranes may be injected and covered with frothy mucus. The kidneys may present reddish-brown markings from altered blood, and degeneration of the epithelium of the tubules and Malpighian bodies.