_Post-mortem Appearances._—The body is generally livid, the countenance pallid, or sometimes livid and bloated, the jaws firmly closed, and the hands clenched. There is frequently blood or froth about the mouth, and the eyes are sometimes described as prominent and glistening. There is often an odor of prussic acid about the body, which is more perceptible on opening the stomach. The venous system is usually gorged with blood; and the brain, lungs, heart, liver, spleen, and kidneys have been found congested with dark-colored fluid blood. _Treatment._—There is no chemical antidote to this poison which can be relied upon. Chlorine and the mixed oxides of iron have been recommended; but even if one of these agents happened to be at hand, it is doubtful if its employment could be timely enough to be advantageous. Attempts must be made to restore animation by cold affusion, stimulating frictions to the chest and abdomen, warmth to the surface, and the application of ammonia to the nostrils. Cold affusion over the head and neck has proved most efficacious when promptly resorted to, and repeated at short intervals so as to cause a shock. The direct injection of liquor ammoniæ into the veins, as proposed by Professor Halford, for snake bite, might be tried if the means were at hand. As soon as possible ammonia should be given internally and the stomach emptied. If recovery ensue from the immediate effects, vomiting should be produced by emetics or otherwise, after which strong coffee, with brandy, ought to be administered. _Tests._—The best are the following: When hydrocyanic acid has to be separated from organic substances, such as the contents of the stomach, it is usual to take advantage of its ready volatility. If the acid be not in combination it may be given off so readily as to be detected by a watch glass moistened with nitrate of silver held over the vessel containing the acid; but in order to make sure of its presence or absence the following process should be adopted. The suspected material should be acidulated with pure sulphuric acid so as to insure the prussic acid being in a free state. The substances thus acidulated are to be placed in a retort, distilled over a water bath, and the distillate collected in a cool receiver containing some caustic potass. About one-sixth of the fluid substance should in this way be distilled over, when the liquid in the receiver may be tested by the silver or iron tests, or the vapor as it passes over may be tried with the sulphur test. 1. The peculiar _odor_ of prussic acid is well known, and is a very delicate test, taken in conjunction with others, of its presence.