In old times, when the teachings of Hippocrates were more in vogue than at this date, when Aristotle and Galen and Ibn Sina and Paracelsus made their contributions to contemporary medical science, it was the custom to regard man in terms of the cosmos. They classified all disorders in a comprehensive manner as accidental or incidental, as acute or chronic, as functional or organic. The functional powers were governed by the Moon, the organic constitution by the Sun. Accidental and acute ailments were ascribed to the action of Mars, incidental and chronic disorders to Saturn. Mars was responsible for all inflammatory action and fevers, while Saturn was the cause of all morbid diseases and loss of vitality. It was only a question of the distribution of the vital principle in man, and this, originating in the Sun and regulated by the Moon, induced fevers when in excess and morbid disease when deficient in any organ of the body. Jupiter was the great healer and arbiter of destiny, and it was his aid that the physician invoked when at the head of his prescription he wrote the symbol ℞—Help, O Jupiter! This ancient custom, together with many of the terms of ancient usage, is retained by modern physicians, many of whom see no more in it than the letter R, the initial of the word Recipe. But we still speak of chronic diseases, while tracing nothing to the action of Kronos (Saturn). We own to a _solar_ plexus and a _semilunar_ ganglion, and there are many other terms which have survived the practice of putting new names to old facts when some new function or structural peculiarity comes under modern observation. Had the ancients known of the existence of Uranus they would have had a potent cause for paralysis, nervous lesion and similar disturbances of the organism, while in Neptune they would have found the cause of anæmia, consumption and wasting decline, and possibly of neurasthenia and the various effects of nervous depletion.