[3] A detailed description of this machine is given in U. S. Dept. of Agr. Cir. 78, entitled "A Machine for Trimming Camphor Trees." 1920.
The cuttings are hauled from the field to the distilling plant, and if many large branches are present they are run through a heavy ensilage cutter. For distillation they are packed in large iron retorts, to which steam is admitted at the bottom. The outlet pipe of the retort is connected with a specially constructed condensing apparatus in which the oil and camphor carried over by the steam are condensed and partly collected. Portions of oil and camphor not collected in the condenser are caught in a tub fitted with an outlet siphon which carries away the excess condensed steam but leaves the oil and camphor behind.
When removed from the condenser the product is very crude, consisting of a mixture of oil, water, and camphor. This mixture is either thrown into a centrifuge and the oil and water removed or it is placed in large cylindrical vats and the oil and water allowed to drain out. The oil is then separated from the water by means of a siphon. The camphor and oil are marketed separately.
The annual yield of cuttings has varied from 2 to 5 tons per acre, which should give approximately 40 to 100 pounds of marketable camphor. At present the planting of small areas does not seem advisable, in view of the heavy outlay required for the machinery necessary to produce camphor gum at a profit. An area of less than 500 acres would probably not warrant the installation of the machinery necessary for the commercial production of camphor, and 1,000 acres or more will doubtless give a greater net return per acre. Although the crop is a low-priced one, under favorable conditions it is estimated that a fair return per acre may be expected, but the data so far accumulated are not sufficient to warrant specific statements concerning the profitableness of the industry.
Camphor oil, or the oil from which camphor has been removed, is used in Japan for illuminating purposes, and as a solvent for resins in the manufacture of lacquer. It is used in Europe for its safrol content, and may probably be utilized for the same purpose in this country. There exists already in the American market a demand for the Japanese oil at prices ranging from 11 to 14 cents per pound.
Camphor imports into the United States usually exceed 3,000,000 pounds annually; hence, it does not seem probable that there is any danger of overproduction in the Southern States. However, it is possible that at times camphor may be imported at a price so low as to render production in this country financially unprofitable.
[CANNABIS.]
The drug cannabis or Indian hemp (Cannabis sativa), consists of the dried flowering tops of the female plants. It grows well over a considerable portion of the United States, but the production of the active principle of this plant is believed to be favored by a warm climate. For drug purposes, therefore, this crop appears to be adapted to the Southern rather than to the Northern States.
Cannabis is propagated from seeds, which should be planted in the spring as soon as conditions are suitable, in well-prepared sandy of clayey loam at a depth of about an inch in rows 5 or 6 feet apart. The seeds may be dropped every two or three inches in the row or planted in hills about a foot apart in the row, 6 to 10 seeds being dropped into each hill. Two or three pounds of seed per acre should give a good stand. About half the seeds will produce male plants, which must be removed before their flowers mature; otherwise, the female plants will set seed, thereby diminishing their value as a drug. The male plants can be recognized with certainty only by the presence of stamens in their flowers.