The predecessors of hospitals are hospices, whose existence in Buddhist countries, in Ceylon, and in the realms of Antiochus and his vassals is already reported by a rock inscription from the middle of the 3rd century BC. According to Bühler, detailed descriptions of the facilities of hospitals or dispensaries can be found in the Puranas, such as in the Nandi and Sandapurana. The Sinhalese historical work "Mahavanao" is said to contain information about hospital facilities in Ceylon, and the Sash Nameh includes reports on Persian hospitals. The word "Maristan," which the Arabs use for hospital, is a Persian word. The "Jatreien" in Greece were roughly equivalent to our polyclinics. In later times, the Romans had "Valetudinarien," rooms for the accommodation of sick slaves and soldiers. The Valetudinaria castrorum is said to have been established according to Hyginus.