[941] See B. xxxi. c. 46, as to the “nitrum” of Pliny. Galen, in describing the manufacture of “santerna,” omits the nitre as an ingredient.

[942] “Argentosum.” The “electrum,” probably, mentioned in c. 23.

[943] As to the “cadmia” of Pliny, see B. xxxiv. c. [22].

[944] “Plumbum album.” Tin, most probably. See B. xxxiv. cc. [47], [48], [49]. Also Beckmann’s Hist. Inv., Vol. II. p. 219, Bohn’s Edition.

[945] Of doubtful identity. See B. xxxiv. c. [48].

[946] See Chapter [19] of this Book.

[947] “Thracius lapis.” This stone, which is mentioned also by Nicander, Galen, Simplicius, and Dioscorides, has not been identified. Holland has the following Note on this passage: “Which some take for pit-cole, or sea-cole rather, such as commeth from Newcastle by sea; or rather, a kind of jeat (jet).” In either case, he is probably wide of the mark, neither coal nor jet igniting on the application of water.

[948] Or mistletoe.

[949] In due succession to gold.

[950] See B. xxxiv. cc. [47], [53].