DIOCLES CARYSTIUS, a famous Greek physician, said by Pliny[401] to have been next in age and fame to Hippocrates himself, lived in the fourth century B.C. He wrote several treatises on medicine, of which the titles and some fragments are preserved by Galen, Cælius Aurelianus, Oribasius, and others. His letter to King Antigonus, entitled “An Epistle on Preserving Health,” is inserted at the end of the first book of Paulus Ægineta, and was probably addressed to Antigonus Gonatus, king of Macedonia, who died B.C. 239. This treatise is so valuable a summary of the medical teaching of the time that it will be useful to insert it in this place. “Since of all kings you are the most skilled in the arts, and have lived very long, and are skilled in all philosophy, and have attained the highest rank in mathematics, I, supposing that the science which treats of all things that relate to health is a branch of philosophy becoming a king and befitting to you, have written you this account of the origin of diseases, of the symptoms which precede them, and of the modes by which they may be alleviated. For neither does a storm gather in the heavens but it is preceded by certain signs which seamen and men of much skill attend to, nor does any disease attack the human frame without having some precursory symptom. If, then, you will only be persuaded by what we say regarding them, you may attain a correct acquaintance with these things. We divide the human body into four parts: the head, the chest, the belly, and the bladder. When a disease is about to fix in the head, it is usually announced beforehand by vertigo, pain in the head, heaviness in the eyebrows, noise in the ears, and throbbing of the temples; the eyes water in the morning, attended with dimness of sight; the sense of smell is lost, and the gums become swelled. When any such symptoms occur, the head ought to be purged, not indeed with any strong medicine, but, taking the tops of hyssop and sweet marjoram, pound them and boil them in a pot, with half a hemina of must or rob; rinse the mouth with this in the morning before eating, and evacuate the humours by gargling. There is no gentler remedy than this for affections of the head. Mustard in warm, honied water also answers the purpose very well. Take a mouthful of this in the morning before eating, gargle and evacuate the humours. The head also should be warmed by covering it in such a manner as that the phlegm may be readily discharged. Those who neglect these symptoms are apt to be seized with the following disorders: inflammations of the eyes, cataracts, pain of the ears as if from a fracture, strumous affections of the neck, sphacelus of the brain, catarrh, quinsy, running ulcers called achores, caries, enlargement of the uvula, defluxion of the hairs, ulceration of the head, pain in the teeth. When some disease is about to fall upon the chest, it is usually announced by some of the following symptoms: There