Nitrum, nitri, n g Plin. Saloiter. G. Agricola. A matter much like salt of colour light ruddle, or whit with holes like a spung. It is falsely taken of some for salt peter.Lapidosum nitrum, Vide LAPIS.Radens tubera nitrum Ouid. Rubenti nitri spuma. Oui. Nitrôsus. pen. prod. Adiect. Plin. Hauing the sanour of Nitrum. Nitrolus locus. Pli. A place where much Nitrum is.
Lewis and Short: Latin dictionary
nĭtrum, i, n., = ni/tron, also called sal nitrum, native mineral alkali, native soda, natron; found chiefly in Media, Egypt, Thrace, and Macedonia, Plin. 31, 10, 46, 106: flos nitri, Vitr. 7, 11, 1; and used for washing with: laveris te nitro, Vulg. Jer. 2, 22; Isid. Orig. 16, 2.—Hence, II.Transf.: censuram lomentum aut nitrum esse, Cael. ap. Cic. Fam. 8, 14, 4.