one particular, that the quantity of coals was diminished and the
air-draught increased according as the process of smelting drew near
to its termination, which involved the removal of the carbonaceous
compound by oxidation. Santos found, by repeated experiment, that even
from ores of the mean standard of twenty per cent, only from eight to
ten per cent of black copper was extracted by the third operation; so
that between eight to twelve per cent still remained in the residuum
or porous quartz of the operation.

[Tagalog women traders.] It was difficult to procure the necessary
means of transport for my baggage on the return journey to Paracale,
the roads being so soaked by the continuous rains that no one would
venture his cattle for the purpose. In Mambulao the influence of
the province on its western border is very perceptible, and Tagalog
is understood almost better than Bicol; the Tagalog element being
introduced amongst the population by women, who with their families
come here, from Lucban and Mauban, in the pursuit of trade. They buy up
gold, and import stuffs and other wares in exchange. The gold acquired
is commonly from fifteen to sixteen carats, and a mark determines
its quality. The dealers pay on the average $11 per ounce; but when,
as is usually the case, it is [Miners uncertain returns.] offered in
smaller quantities than one ounce, only $10. [136] They weigh with
small Roman scales, and have no great reputation for honesty.

North Camarines is thinly inhabited, the population of the mining
districts having removed after the many undertakings which were
artificially called into existence by the mining mania had been
ruined. The goldwashers are mostly dissolute and involved in debt,
and continually expecting rich findings which but very seldom occur,
and which, when they do occur, are forthwith dissipated;--a fact