Cuiaba pays for these things in diamonds, gold dust, and hides. The diamond region is, as I have before said, in the neighborhood of the village of Diamantino, situated on the high lands that divide the headwaters of the tributaries of the Amazon and La Plata. M. Castelnau visited this country, and I give the following extracts from his account of it. He says:
"The mines of gold, and especially those of diamonds, to which the city of Diamantino owes its foundation and its importance, appear to have been known from the time the Paulistas made their first settlements in the province of Matto Grosso; but, under the Portuguese government, the working of the diamond mines was prohibited to individuals under the severest penalties.
"A military force occupied the diamond districts, and watched the Crown slaves who labored in the search of this precious mineral. Every person finding one of these stones was obliged to remit it to the superintendency of diamonds at Cuyaba, for which he received a moderate recompense, whilst he would have been severely punished if detected in appropriating it.
"At this period, throughout Brazil, the commerce in diamonds was prohibited, as strictly as their extraction, to all except the special agents named by the government for this purpose.
"Subsequently to the government of João Carlos, of whom we have already spoken, this commerce became more or less tolerated, then altogether free.
"If, as we are assured, the laws which heretofore governed this branch of industry are not legally repealed, they have at least completely fallen into disuse. The inhabitants of Diamantino only complain that the prohibition of the slave trade renders it impossible for them to profit by the wealth of the country.
"In 1746 valuable diamonds were found, for the first time, in Matto Grosso, and were soon discovered in great quantities in the little river of Ouro. The governor, Manuel Antunes Nogueiza, designing to take possession of these lands for the benefit of the Crown, ejected the inhabitants therefrom. Famine made great ravages among the wretches thus deprived of their homes.
"From that time the country seems to have suffered every evil. A long drought was followed by a terrible earthquake on the 24th September, 1746. It was not until May 13, 1805, that the inhabitants were again permitted to take possession of their property, but upon condition of remitting to the Crown, under severe penalties, all the diamonds found.
"In 1809 a royal mandate established at Cuyabá a diamond junta.
"Gold and diamonds, which are always united in this region, as in many others, are found especially in the numerous water-courses which furrow it, and also throughout the whole country.