§ 51. Where the infirmary buildings stood due east of the cloister, as at Canterbury, they were approached by a passage through the east range, next the chapter-house. Their position, however, was variable; and in such instances the infirmary passage represented a bay cut off from the vaulted undercroft of the dorter, which formed the rest of the ground-floor of the eastern range. At Westminster, where this sub-vault belongs to the earliest portion of the monastery, the ordinary custom was followed of dividing it into two apartments. The northern and smaller, occupying the two bays at the south end of the east walk, was the treasury, known at Westminster as the chapel of the Pyx, because the currency, contained in a box or casket (_pyxis_) was brought there for trial. The southern division extended for five bays beyond the cloister, and was the common house or warming-house (_calefactorium_), which contained the fireplace where the monks warmed themselves in winter. In Cluniac monasteries this was also the bleeding-house of the monks. If, however, the Westminster arrangement may be quoted as typical, it was not invariable. The customary position for the warming-house was beneath the dorter; and consequently, if the dorter, as sometimes happened, occupied an abnormal situation, the warming-house followed suit. Thus, on the contracted site at Gloucester, the dorter was on the first floor of a building at right angles to the cloister, parallel to the chapter-house. At Worcester, it was at right angles to the west walk of the cloister. Probably the early plan at Durham was like that at Westminster, but eventually the dorter and common house were removed to the west range. The plan of St Agatha's, which in more than one respect resembles that of Durham, also shews the dorter and common house in the west range; but, while the treasury at Durham was the part of the dorter sub-vault between the common house and the church, the treasury at St Agatha's, as in many canons' houses, was probably the sacristy in the east range, between the church and chapter-house, where at Durham we find the parlour. The dorter and common house at Canterbury were in the usual place; but the treasury was in quite a different part of the monastery, between the infirmary and one of the chapels of the apse; and at Gloucester, at any rate after the fourteenth century, the treasury was a first-floor room above the monks' parlour, between the chapter-house and north transept[8].