88 CHAPTER 4 THE ECONOMIC FOUNDATIONS OF COLONIAL LIFE
An equally rapid increase of horses, mules,
and cattle took place in the vast, rich pampas (grass-
lands) of the Río de la Plata (modern Argentina).
Their increase in this area of almost infi nite pastur-
age soon outstripped potential demand and utiliza-
tion, and herds of wild cattle became a common
phenomenon in La Plata, as in other parts of Span-
ish America. Barred by Spanish law from seaborne
trade with the outside world, the inhabitants of this
remote province, lacking precious metals or abun-
dant native labor, relieved their poverty by illegal
commerce with Dutch and other foreign traders,
who carried their hides and tallow to Europe. In
addition, they sent mules and horses, hides and tal-
low to the mining regions of Upper Peru (Bolivia).
Another center of the cattle industry was the
West Indies. José de Acosta wrote in 1590 that
the cattle have multiplied so greatly in Santo
Domingo, and in other islands of that region
that they wander by the thousands through
the forests and fi elds, all masterless. They hunt
these beasts only for their hides; whites and
Negroes go out on horseback, equipped with a
kind of hooked knife, to chase the cattle, and
any animal that falls to their knives is theirs.
They kill it and carry the hide home, leaving
the fl esh to rot; no one wants it, since meat is
so plentiful.COLONIAL MINING AND INDUSTRY
Mining, as the principal source of royal revenue
in the form of the quinto (the royal one-fi fth of
all gold, silver, or other precious metals obtained
in the Indies), received the special attention and
protection of the crown. Silver, rather than gold,
was the principal product of the American mines.
Spain’s proudest possession in the New World was
the great silver mine of Potosí in Upper Peru, whose
fl ow of treasure attained gigantic proportions be-
tween 1579 and 1635. Potosí was discovered in
1545; the rich Mexican silver mines of Zacatecas
and Guanajuato were opened up in 1548 and
- In the same period, important gold placers
(sand or gravel deposits containing eroded par-
ticles of the ore) were found in central Chile and in
the interior of New Granada (Colombia).
At fi rst silver was processed by the simple and
inexpensive technique of smelting, in which the
ore was broken up by the use of heavy iron ham-
mers and stamping mills, and then fi red in furnaces
using charcoal or other fuel. But smelting was
labor-intensive and heavily dependent on adequate
supplies of fuel, which created serious problems for
an Andean mining center like Potosí, located high
above the timberline, or the Mexican center of Zaca-
tecas, situated in a semiarid area far from the densely
populated central zone from which it needed to draw
its work force. Thus, in 1556 the introduction of the
patio or amalgamation process, which used mercury
to separate the silver from the ore, gave a great stim-
ulus to silver mining. The chief source of mercury for
Potosí silver was the Peruvian Huancavelica mine,
whose health hazards and wretched working condi-
tions made labor there “a thing of horror.” Mexican
silver was chiefl y processed with mercury from the
Almaden mine in Spain.
Lack of capital to fi nance technical improve-
ments required by the gradual exhaustion of veins
and increasing depth of mines, fl ooding, and other
problems, combined with the high cost of mercury
(a crown monopoly), caused a precipitous decline
in silver production at Potosí after 1650. But this
decline was at least partly offset by the rise of new
Peruvian centers like Oruro and Cerro de Pasco. In
Mexico, production levels fl uctuated, with output
declining in some old centers like Zacatecas and ris-
ing in new ones like Parral, but here the long-range
trend for the seventeenth century seems to have
been upward. Notwithstanding earlier historians’
claims that an acute labor shortage caused by the
catastrophic fall of the native population was the
root cause of a supposed decline in silver production
in New Spain, it now appears that mine owners in
general had no diffi culty fi lling their labor needs.
After 1650, in both Peru and Mexico, silver mining
shifted from large centers like Potosí and Zacatecas
to small, dispersed, and mobile mining camps. In
the same period many mine owners abandoned the
amalgamation process, based on scarce and costly
mercury, in favor of smelting. Because the quantity
of mercury a mine owner purchased gave royal of-