part iii

, pp. 576-580). He states that the Igorrotes have always refused, even to the present day, to allow any outsiders, of any race, to visit the quartz mines in their country.

[60] "Roasted and powdered copper pyrites added to ores of silver when reduced to the state of a magma [_i.e._, a thin paste], in order to reduce the horn silver; formerly so called at the Spanish mines of Mexico and South America" (Webster's _Dictionary_).

"The _magistral_ is a mixture of pyritous copper and sulphuretted salt, roasted for some hours in a reverberating oven, and slowly cooled" (Humboldt's _New Spain_, Black's trans., iii, p. 260).

[61] Spanish, _greta_, an old word used for _almártaga_; oxide of lead in the form of small scales, and lustrous; commonly called "litharge of silver," or "of gold," as it resembles those metals.

[62] Also written _temesquitato_; a Mexican word, applied to the dross from the surface of lead into which pulverized silver ore is introduced.

[63] See Humboldt's account of the mining methods and processes in vogue in Nueva España, in his _New Spain_ (Black's trans.), iii, pp. 231-280.

Various laws and ordinances concerning the discovery and operation of mines in the Spanish colonies may be found in _Recopilación de leyes_. mainly in lib. iv, tit. xix, xx, and lib. viii, tit. xi.

[64] The first figure refers to the number of onzas loss of quicksilver, and the second to the number of the assay. Thus ten onzas of quicksilver were lost in the second assay.