This city is surrounded almost on every side by a lake, with the exception of one part, which may be about three hundred paces in length, which can be cut and fortified. On this side only is there anything to be feared, as on all the other sides it is more than a league to the borders of the lake, into which fall four great rivers from far inland, and navigable for boats. One is called the river of Terra-Firma; another the river of Chile; another the river of Cacou; and the fourth, the river of Mechique, in which great quantities of fish are caught, of the same kind as we have with us, and very good. Along this river are a great number of fine gardens, and much arable land, very fertile. Two leagues from the said Mechique there are silver mines, which the king of Spain has farmed out for five millions of gold a year, and he has reserved also the right of employing a great number of slaves, to get from the said mines as much as he can, for his profit; and he draws besides the tenth part of all that the farmers get, so that these mines are a very good revenue to the said king of Spain. A great quantity of cochineal is gathered in this country, which grows in the fields as peas do elsewhere. It comes from a fruit the size of a walnut which is full of seed within.[59] It is left to come to maturity until the said seeds are dry, and then it is cut like corn and beaten to have the seed, of which they sow again so as to have more. It is the king of Spain alone who has the said cochineal sown and collected; and the merchants must buy it of his appointed officers, for it is merchandise of high price, and is esteemed as gold and silver. [59] "Cactus Opuntia." The belief that the cochineal was the seed of a plant, was prevalent for a very long period after the conquest of Mexico. In a drawing which Champlain gives of the plant, the "seeds" are shown exactly as the insects fix and feed on the leaves. The jealousy of the Spanish government, and the severe monopoly of this production, prevented the true nature and mode of propagation from being known, and gave rise to a variety of fables and conjectures. There is a tree in the said country which is cut like the vine, and from the place where it is cut there distils an oil, which is a kind of balm, called oil of canima, from the name of the tree which is so called.[60] This is a singular oil for all sorts of wounds and cuts, and for removing pains, principally of gout. The wood has the odour of fir-tree wood. An ounce of the said oil is worth and sells for two crowns. [60] I am at a loss to find what tree it is that Champlain designates thus, unless it is "Canica"--Myrtus pimenta.