The profits which are obtained in favourable years by the planters of cotton, are enormous; but frequently disappointments are experienced. Oftentimes a whole crop is totally lost, and instead of large returns, the year proves entirely unproductive; or after a fair promise, the grub, the caterpillar, the rain or the excessive drought destroys all hope until the following season. The other great agricultural object,—the sugar-cane, is not subject to these numerous and ruinous reverses; for even if the year is unfavourable, at least enough to pay the expences may be expected. I have heard it urged that the market is very little affected by the supposed failure of a crop; but it must be remembered that in a country of such vast extent, one quarter may escape all mishap, whilst another is unfortunate.[171] The quality of the cotton which is produced in South America, either to the north or south of Pernambuco, is inferior to that of the province of which I am treating. The cotton of Seara is not so good, and the cotton of Maranham is still coarser. Cotton is the staple commodity of both these ports. Proceeding from Pernambuco to the south, the cotton of Bahia is not so fine, and the small quantity which is produced at Rio de Janeiro is not so good as that of Bahia. In treating of sugar and cotton, I have stated the chief points in which the planters in the Columbian islands and those of Brazil principally differ. Those of my readers to whom this subject is particularly interesting may be referred to the well known work which I have consulted.[172] THE MANDIOC PLANTS. THE mandioc requires good land, and the same spot will not produce two crops successively; it must be allowed to rest for one or two years or more. The operation of planting it is simple, and differs in no respect from that which was practised formerly by the Indians[173]. The flour which is made from this root is called _farinha de pao_, or stick flour[174]. There are several species of the mandioc plant, of which some are adapted to high lands, and others to low and moist situations; but when the plant is cultivated upon the latter, hillocks must be raised, else the root would decay. Cattle are fed upon the root and stalk: these are first prepared by being cut into small pieces and exposed to the sun for several hours; if this was not done, the food would be injurious to them. I have however seen some of the draught oxen that have become so habituated to it as to eat the root quite fresh, without receiving any apparent injury;—in the manner that the human body becomes callous to the most violent medicines by long custom.