Page:Transactions of the Provincial Medical and Surgical Association, volume 1.djvu/57

 mortem, being the result of those physical and chemical laws to which all inorganic matter is subject, and to which all organised bodies are also subjected when the vital spark ceases to animate them. The first three of these I shall pass over as not essential to my present purpose, confining my observations to the last, which comprises the several sources of fallacy by which anatomists, in the examination of bodies after death, are most liable to be misled.

The contractility of tissues which resides in the small arteries, continuing after the heart has ceased to beat, hyperæmia may be produced at the moment of death, and thus appearances may be presented in which the morbid actions, antecedent to death, had no share.

But hyperæmia may also be produced at certain periods after death, from several causes. Of these, hypostasis, or dependent position, is the most remarkable. The phenomena of this, as frequently exhibited in the skin, are familiar to all, and cannot be mistaken. But it continually takes place in internal parts, and may be produced at pleasure according to the position in which the body is placed. The degree is also influenced by the time which intervenes between death and dissection. A body, partially examined, will present different phenomena, and exhibit other congestions, if the examination be renewed the following day.

During life, the blood contained in its vessels can pass off only by their extremities, the vital powers of the tissues preventing transudation through their sides. There is reason to believe, however, that,