A very curious regulation was that if the physician got drunk and anybody insulted him, he could claim no recompense, because “he knew not at what time the king might want his assistance.” The physicians of Myddvai flourished in the time of Rhys Gryg in the early part of the thirteenth century. His domestic physician was Rhiwallon, who was assisted by his three sons Cadwgan, Gruffydd, and Einion. They lived at Myddvai, in the present county of Caermarthen. By command of the prince, these physicians made a collection of the most valuable prescriptions for the treatment of the various diseases of the human body. This collection was not reduced to writing previously, though many of the recipes were no doubt in use some centuries before. The original manuscript is in the British Museum, and there is a copy in Jesus College, Oxford, in the _Red Book_, which has been published with an English translation by the Welsh MSS. Society.[675] The descendants of this family of physicians continued to practise medicine without intermission until the middle of the last century. This most interesting volume also contains a second portion, which purports to be a compilation by Howel the physician, son of Rhys, son of Llewelyn, son of Philip the physician, a lineal descendant of Einion the son of Rhiwallon. Some medical prescriptions assumed the form of proverbs such as the following:— MEDICAL MAXIMS. (_From the Book of Iago ab Dewi._) “He who goes to sleep supperless will have no need of Rhiwallon of Myddvai. A supper of apples—breakfast of nuts. A cold mouth and warm feet will live long. To the fish market in the morning, to the butcher’s shop in the afternoon. Cold water and warm bread will make an unhealthy stomach. The three qualities of water: it will produce no sickness, no debt, and no widowhood. To eat eggs without salt will bring on sickness. It is no insult to deprive an old man of his supper. An eel in a pie, lampreys in salt. An ague or fever at the fall of the leaf is always of long continuance, or else is fatal. A kid a month old—a lamb three months. Dry feet, moist tongue. A salmon and a sermon in Lent. Supper will kill more than were ever cured by the physicians of Myddvai. A light dinner, a less supper, sound sleep, long life. Do not wish for milk after fish. To sleep much is the health of youth, the sickness of old age. Long health in youth will shorten life. It is more wholesome to smell warm bread than to eat it. A short sickness for the body, and short frost for the earth, will heal; either of them long will destroy. Whilst the urine is clear, let the physician beg. Better is appetite than gluttony. Enough of bread, little of drink. The bread of yesterday, the meat of to-day, and the wine of last year will produce health. Quench thy thirst where the washerwoman goes for water. Three men that are long-lived: the ploughman of dry land, a mountain dairyman, and a fisherman of the sea.