Once the tobacco is cut there begin chemical changes in the leaves that are of great importance to its subsequent flavor and use. These are aided or induced first by a process of curing, which is accomplished by suspending the wilted leaves in the sun, a process that has been practically abandoned for curing by artificial heat. The leaves are hung in a building where slow fires bring the temperature up to 150 degrees F., which is maintained for a few days. The cured tobacco is then gathered into small bundles which are stacked or packed so closely that fermentation begins, often generating a temperature of 150 degrees F. The bundles are then reshifted and the process allowed to start again, which may be done several times, depending upon the quality of the leaf, flavor desired, and commercial requirements. Enzymes and bacteria play a large part in the fermentation process and inoculation of poor grades of tobacco with the organisms of finer grades has been tried. After fermentation has been stopped practically all tobaccos are aged for at least two years, some for longer periods. In Cuba, where its use was first noticed, the finest tobacco in the world is still produced, notably in the province of Pinar del Rio. It is still something of a mystery as to what peculiar combination of soil, climate, or handling the unquestionable superiority of the Cuban leaf is due. For one thing it is grown in the open, without shade, and is never cured by artificial heat. Nor is the very excellent cigarette tobacco of Turkey ever artificially cured. But attempts to imitate the conditions under which these finest grades of tobacco are produced outside Cuba and Turkey have never been really successful, so that those countries have practical monopolies on the production of the finest cigars and cigarettes. The weed is cultivated nearly throughout the world, even Canada producing considerable quantities, but the best kinds and greatest production is in warmer regions. It is second only to the sugar crop in Cuba, and the United States produces over one-third the world’s total supply. Immense quantities are grown, however, in India and Sumatra, and in the Philippines. Perhaps the most unusual and localized conditions of climate and subsequent handling are found in the production of perique tobacco. All the world’s supply is grown on a ridge at Grand Point, in the parish of St. James, Louisiana. The leaves are subjected to great pressure and the expressed juice, after oxidation, is reabsorbed by the leaves after the pressure is removed. The peculiar flavor is apparently due to this and to the damp climate. Perique is now used throughout the world as an ingredient of the better kinds of pipe tobacco.