disease, by accident, or of old age. And as disease is an accident, we may naturally ask if what we call old age is not also a disease.
However that may be, the mortal process, being never instantaneous, has a duration, a beginning, a development, an end—in a word, a history. It constitutes an intermediary phase between perfect life and certain death.
Necrobiosis. Atrophy. Degeneration.—The process according to the circumstances may be shortened or prolonged. When death is the result of violence events are precipitated. The physical and chemical transformations of the living matter constitute a kind of acute alteration called by Schultze and Virchow necrobiosis. According to the pathologists, there are two kinds of necrobiosis:—that by destruction, by simple atrophy, which causes the anatomical elements to disappear gradually without undergoing appreciable modifications; and necrobiosis by degeneration, which transforms the protoplasm into fatty matter into calcareous matter, into granulations (fatty degeneration, calcification, granulous degeneration). There is no disagreement as to the causes of this necrobiosis. They are always accidental; they originate in external circumstances:—the insufficiency of the alimentary materials, of water, of oxygen; the presence in the medium of real poisons destroying the organized matter; the violent intervention of physical agents, heat, electricity; the reflex on the composition of the cellular atmosphere of a violent attack on some essential organ, the heart, the lungs, the kidneys.
Senescence. Old Age.—In a second category we must place the mortal processes, slow in their move-
