The north side of the chapel has been propped at a late period by three sloping buttresses. At its western end is a doorway, the jambs of which seem original, while the pointed head is later. About half-way along this side is one of those 'low side windows' through which, it is supposed, the Sacrament was administered to lepers--indeed, the leper-house stood on this side of the chapel.[127] Though of limestone, this small lancet window, with its arch and dripstone trefoiled, is apparently of the thirteenth century, and an early example of its class. East of it are, first a Perpendicular window of two lights--late in character, and second a partially-blocked and possibly original doorway, perhaps for the priest, (though priests' doors are usually on the south side). Its outer arch is rounded, while the inner is pointed and has perhaps been altered. The east window is broad, finely arched, and surmounted by a bold dripstone terminating in heads. Its four lights, partially blocked, are round-headed, with rather large cusps, and in the upper part of the window there is much tracery, in which perpendicular lines lead up to arches that intersect. Indeed it is difficult to say whether this fine window is an example of late Perpendicular, or of the transition to that style from the Decorated. It is on the south side that the irregularity in the size, spacing, and level of the windows in this chapel is most marked. Here toward the eastern end is a square-headed Perpendicular window of two lights, much resembling the south window at St. Anne's Hospital, and surmounted by a square label. Next comes a small lancet, probably Early English, with no limestone about it. The next window is tall, rectangular, and without tracery, but the stump of a mullion remains on the sill, which is of gritstone. West of this is the principal entrance, a Norman arch, beneath which a pointed arch has been inserted, the original imposts, however, remaining. The upper arch is enriched with the chevron, and its dripstone with two rows of the round billet arranged chequerwise and with a moulding composed of a series of little crosses, rather suggestive of the dog-tooth.