Fine Para is best quality rubber made from the richest kinds of Hevea milk. It is cured through and through, whilst the latex is being coagulated, with the smoke of palm-nuts. The nuts most commonly used in the Amazon region are the fruit of the urucuri palm, which flourishes in the forests where the Heveas are found. Various products are turned to account as fuel for curing rubber in other parts of the world, but the results, taken as a whole, have led to a general opinion that the smoke of the palm-nuts used in the Amazon country plays an important part in keeping the rubber of this region first of all rubbers as regards quality; but the secret of this smoke’s special power has not yet been discovered. Entrefine or medium Para is made from Hevea milk other than the very richest; or it may be the result of best quality milk which has only been indifferently well cured. Coarse Para, or negro-heads, is uncured or partly cured refuse. When a tree has been tapped, some of the milk in the collecting-cups cakes into a thin crust on the inside of the bowls, and drops fall and congeal on the rim and outer surface. The scraps have to be cleaned off the cups every morning, for new milk loses much of its value if it is allowed to come into contact with dirt or refuse; sometimes they are thrown away, but frequently they are hoarded in a bag which the seringueiro takes with him on his tapping round for this particular purpose. The refuse is well worth saving, for it will fetch quite a good price as negro-heads. But such coarse rubber is not always an extra source of income to the seringueiro. Sometimes he loses considerably by it, for he finds himself, through no fault of his own, with nothing but this poor quality material as the reward for his day’s toil. If it rains hard whilst the trees are being tapped, the latex curdles in the collecting-cups, and the seringueiro has to collect a supply of negro-heads instead of fresh milk. Again, the milk sometimes coagulates much too quickly when it is being cured; the material produced is then negro-heads instead of fine or even medium Para. In the commercial world Para rubber has many secondary names, which tell from which particular district such or such a supply has been obtained. The chief rubber-producing regions in the Amazon country are: 1. The Brazilian State of Para, in the Lower Amazon Valley, including the islands in the mouth of the river. One very good quality rubber from this region is called “Caviana,” after the island of that name, where it is obtained. 2. The Brazilian State of Amazonas, in the Upper Amazon Valley. Rubber produced in this State is known generally as “up-river” rubber; it is also called “Manaos,” after the great commercial centre of the industry in this region, or “Madeira,” after a tributary of that name which gives access to some of the richest rubber lands in the State.