Illustrated Companion to the Latin Dictionary/Baptisterium

This article incorporates text from a publication now in the public domain: Rich, Anthony (1849). The illustrated companion to the Latin dictionary, and Greek lexicon. p. vi. OCLC 894670115. https://archive.org/details/illustratedcompa00rich. 

BAPTISTE'RIUM (βαπτιστήριον). Properly a Greek word (Sidon. Ep. ii. 2.), though not extant in any Greek author. A cold plunging bath, constructed in the cella frigidaria. (Plin. Ep. ii. 17. 11. Id. v. 6. 25.) The illustration (Baptisterium/1.1) presents a view of the cold bath, and room which contains it, as now remaining at Pompeii. The bath itself (baptisterium) is a circular marble basin, of 12 feet 9 inches diameter, indented with two steps, and having a short low seat at the bottom (on the left hand in the engraving), upon which the bather might sit and wash.

2. Amongst the ecclesiastical writers, or subsequently to the establishment of Christianity; a building distinct from the church in which the baptismal font was placed (Sidon. Ep. iv. 15.); of which the baptistery built by Constantine near the church of S. Giovanni Laterano, at Rome, affords an actual example. A view of the interior of this edifice may be seen in Gally Knight's "Ecclesiastical Architecture of Italy."

• 
  Baptisterium/1.1