Whether in the mines or by the rivers, whose 'golden sands' are flecked with gems, in rich Brazil, the labour of procuring these beautiful gems is great, and large specimens are rarely found; so rarely, that big diamonds have their histories--terrible histories too often--like heroes and race-horses. They are weighed by the carat, a word which Mr Streeter considers to have been derived from the name of a bean, a species of _Erythrina_, which grows in Africa. 'The tree which yields this fruit is called by the natives "kuara" (sun), and both blossom and fruit are of a golden colour. The bean when dried is nearly always of the same weight, and thus in very remote times it was used in Schangallas, the chief market of Africa, as a standard of weight for gold. The beans were afterwards imported into India, and were then used for weighing the diamond.' It is estimated that in ten thousand diamonds rarely more than _one_ weighing twenty carats is met with, while possibly eight thousand of one carat or less may be encountered. An elaborate system of rewards and punishments is adopted in the Brazilian mining and river-searching works; but it is believed that in spite of this, one-third of the produce is surreptitiously disposed of by the labourers. The histories of those world-famous diamonds the Sancy, the Regent, the Koh-i-noor, the Blue (or Hope) diamond, and others, have been related before, and history and romance have dealt with the misery and crime, the evil passions and the mystic fancies, involved in the stories of some of these. In a few lines Mr Streeter gives a sketch of the Brazilian contribution to this many-chaptered story, which is not generally known. 'The discovery of these precious stones in 1746,' he says, 'proved a great curse to the poor inhabitants of the banks of the diamond rivers. Scarcely had the news of the discovery reached the government, ere they tried to secure the riches of these rivers for the crown. To effect this, the inhabitants were driven away from their houses to wild far-away places, and deprived of their little possessions. Nature itself seemed to take part against them: a dreadful drought, succeeded by a violent earthquake, increased their distress. Many of them perished; but those who lived to return on the 18th May 1805, were benevolently reinstated in their rightful possessions. Strange to say, on their return the earth seemed strewn with diamonds. Often the little ones would bring in between three and four carats of diamonds.'