Year.

Number. Value.

Duty. Rate.

PLANTS, TREES, SHRUBS, ETC. (See also STOCKS, CUTTINGS, AND SEEDLINGS.) The rugosa rose, an ornamental shrub for garden planting, is used in Europe as a stock for grafting. It is grown by all nurserymen handling ornamental shrubs. Ornamental trees are used for street, park, and home-ground planting. They are produced in this country generally in nurseries, the kinds varying with the region. Western Europe, especially France, furnishes a supply for propagating purposes only. Various kinds of broad-leafed evergreens are found mainly in the warmer sections. Most sections produce these shrubs in nurseries. France, Belgium, Holland, and other parts of western Europe cultivate them extensively.

Imports in 1916 of ornamental trees were over 2,000,000; of ornamental shrubs, over 4,000,000; and of evergreens, 2,500,000. The plant quarantine of the Department of Agriculture now prevents the importation of these plant materials.

Exports are insignificant. They are excluded from many European countries.

Nursery and Greenhouse Stock, N. S. P. F. "Nursery and greenhouse stock" is a blanket phrase, including many different plants grown in small quantities.

Production.-Many of these plants are grown to some extent in the United States. Western Europe and Japan are notable producers. Imports since 1917 have been as follows:

1 Of these, 853,000 came from Cuba. As the classification was changed in 1922, the figures are not strictly comparable with those for preceding years.

Exports.-None recorded.

Imported by the Department of Agriculture, Etc. The varieties here included represent plants, trees, seeds, etc., brought in by the Government for experiment and study, and cover a wide range of plant material.

Imports of plants, trees, shrubs, roots, seed cane, and seeds were valued at $32,000 in 1914, and at $47,643 in 1915. Imports since 1917 have been valued as follows: 1918, $5,781; 1920, $5,685; 1922, $10,511; 1923, $2, 360. Exports.-None.

PLASTER OF PARIS. See GYPSUM.

PLASTERS, HEALING OR CURATIVE. Healing and curative plasters are intended for external application. They are usually pliable at the temperature of the body. The plastic material may be "lead plaster" (a lead soap made by beating together equal parts of lead oxide, olive oil, and lard), or it may be a mixture containing crude rubber, or a combination of resinous substances with fats and waxes. The substances are spread upon linen, muslin, paper, or leather. The active principle used in the plaster depends upon the curative action desired."

Adhesive plasters are employed in surgery to keep dressings in place, to cover ulcers, and to strengthen weak muscles. Court-plaster is made by applying to silk a coating of isinglass and tincture of benzoin.

Imports for four years prior to the war averaged a little less than $5,000 in value. Their value was $10,929 in 1914. Later statistics follow:

use in the production of plate or other glass; (2) plates, electrotyped, stereotyped, photo-engraved, etc., and plates of other material than steel, engraved for printing; and (3) lithographic plates of stone or other material, engraved, drawn, or prepared, and wet transfer paper prepared wholly or partly with glycerin and containing imprints taken from lithographic plates.

Production.-The latest available figures cover only part of these materials. In 1921 the country's output of engraved steel and copper plate, including plate printing, amounted to $27,685,000; photo-engraved plates not done in printing establishments, to $24,420,000; and stereotype and electrotype plates, to $13,789,000. The figures for the output of lithographic plates include much other material. England and Germany are large producers of these several articles. Imports in 1914 approximated $50,000. Later statistics follow:

PLATINUM. The crude mineral called platinum is frequently alloyed with iridium, rhodium, palladium, iron, or other metals. It is now of great industrial and military importance and is practically indispensable in the chemical industry. Some of its important uses are in the contact process of making concentrated sulphuric acid, in the delicate parts of the ignition system of internal-combustion engines, in instruments of precision, in photographic paper, in dentistry, and for jewelry.

Production of crude platinum was 450 troy ounces, valued at $20,250, in 1914. In 1922, 54,124 ounces were recovered by domestic refiners and in 1923, 46,780 ounces. California and southwestern Oregon are the principal sources in this country. The domestic output in 1914 was less than 1 per cent of total net imports of platinum and its manufactures. Known deposits do not indicate that the United States will ever produce a substantial part of the platinum supply. World production is small and steadily declining. In 1914 Russia produced 241,200 troy ounces, or 92.57 per cent of the world's total; Colombia, 17,500 troy ounces, or 6.72 per cent; all other countries, 1,848 troy ounces, or 0.71 per cent. In 1916 Russia supplied but 63,900 troy ounces, or 71.05 per cent; Colombia, 25,000 troy ounces, or 27.80 per cent, and all other countries, 1,032 ounces, or 1.15 per cent.

In the United States the metal is derived largely from the residues obtained in the refining of gold, silver, copper, and nickel. Reports from refiners to the Geological Survey indicate a recovery from these sources of 54,142 troy ounces of the metal in 1922.

Imports of unmanufactured platinum were 38,953 troy ounces, valued at $1,418,280, in 1914; of platinum manufactured into ingots, bars, plates, sheet and wire, sponge, or scrap, 54,932 ounces, valued at $2,444,951. Imports of vases, retorts, and other apparatus, vessels and parts of, composed of platinum, for chemical uses, were valued at $82,000 in 1914. Total imports of platinum and manufactures of platinum, including a small quantity of ore, were valued at $3,982,708 in 1914. In 1914 the chief sources of unmanufactured platinum, in order, were Germany, Colombia, and the United Kingdom. More recently supplies have come mainly from Colombia, because of the fact that Russia, owing to her political situation, almost ceased production. Imports of the manufactured forms included under this designation were derived in 1914 from Germany, France, and the United Kingdom, but since the war the United Kingdom has been the main source. The statistics for recent years are as follows (000 omitted):

1 Included in Plates n. e. s., since Sept. 22, 1922.

Exports in 1914 amounted to $72,752. Exports of plates and cuts, electrotype, stereotype, or engraved, for later years have been valued as follows: 1918, $181,020; 1920, $535,597; 1922, $335,243; 1923, $395,949.

Exports.-Statistics not available.
Survey A-14.

PLATES, GALVANIZED. See GALVANIZED

SHEETS, PLATES, ETC.

PLATES, IRON OR STEEL. See IRON OR STEEL PLATES, ETC.; WIRE Rods.

Exports of unmanufactured platinum amounted in 1914 to 273 troy ounces, valued at $12,977. Exports of manufactured platinum in the same year were valued at $71,172, of which about 75 per cent went to Canada. In later years exports have been as follows:

Platinum, unmanufactured:

Troy ounces.
Value..

Platinum, manufactures

of (value)..

1 Includes jewelry.

Survey FL-20.

(See also ORES OF GOLD, SILVER, ETC.) PLATINUM, COMPOUNDS OF. See CHEMICAL COMPOUNDS.

PLATINUM METALS. Iridium is found in platinum ores; as osmiridium, a native alloy of iridium and osmium, in varying proportions; and in the form of native alloys with the other platinum metals. It is a white, steel-like metal, brittle when cold, and somewhat malleable at white heat. The principal sources of these ores are the Ural Mountains, Australia, Colombia, and Borneo. Platinum iridium alloys, which are harder and more resistant to acids than platinum, are used in the manufacture of standard weights, knife edges of balances, and in other articles which must be preserved from atmospheric corrosion. Osmiridium serves in the manufacture of the irridium tips for gold pen points.

Production increased from 193 ounces in 1914 to 10,042 ounces in 1917, and decreased to 3,875 ounces in 1918; to 418 ounces in 1920; to 210 ounces in 1922; and to 280 ounces in 1923.

Imports of iridium were 3,619 troy ounces in 1917. For the years 1918 to 1923 they were as follows:

Palladium is the lightest metal of the platinum group. While found native alloyed with small amounts of platinum and iridium and 5 to 10 per cent of gold and silver, the chief supply comes from the nickel-copper ores of Ontario and the electrolytic refining of copper. Alloyed with gold and silver, palladium has found considerable use as a substitute for platinum in the manufacture of laboratory ware, in jewelry, and for dental and various industrial purposes. It is also added to platinum to make a lighter alloy capable of receiving a brilliant polish. Palladium is used for coating surfaces, e. g., reflectors of searchlights and divided scales on various scientific instruments. Production was 4,024 ounces in 1918; 4,309 ounces in 1920; 1,943 ounces in 1922, and 1,934 ounces in 1923.

Imports in the fiscal year 1918 were 1,317 ounces. For later years they have been as follows:

Troy ounces. Value.

Exports.-None recorded.

Ruthenium, a hard, brittle, infusible metal, is associated with metals of the platinum group. It is very rare and has not been used commercially to any great extent although employed occasionally in dyeing solutions for silks.

Imports in 1915 were 90 troy ounces. years they have been as follows:

Troy ounces.. Value..

Exports.-None recorded.

For later

PLAYING CARDS. Production.-The domestic playing-card industry showed annual sales amounting to about $3,000,000 in 1913. Later statistics follow:

Osmium.

Osmiridium.

Exports.--Export values were $330,194 in 1914. Later exports have been as follows: 1918, $882,370; 1920, $1,173,559; 1922, $681,735; 1923 $1,121,986. PLIERS. See NIPPERS AND PLIERS. PLUMBAGO. See GRAPHITE OR PLUMBAGO. PLUMS, GREEN OR RIPE. Three main types of plums are grown in America-the European or Domestica, the Japanese, and the numerous native species. The European and Japanese types are used principally fresh and for canning; the native plums, to a limited extent fresh, for canning, marmalades, jellies, etc. Certain European plums, damsons, for example, are used entirely for preserves and marmalades.

Production of plums and prunes in 1909 was 15,480,170 bushels, the Pacific States yielding over 80 per cent. In 1919 production amounted to 19,500,000 bushels, valued at $41,900,000.

The types are somewhat regional, commercial production of the European varieties being chiefly in New York, Michigan, Ohio, California, and the Pacific Northwest. The native species are hardiest and more widely distributed. In 1919 a total of 571,521 cases of plums, valued at $2,228,183, was canned as compared with 288,326 cases, valued at $438,238, in 1914. About twothirds of the pack is canned in California.

Imports of plums, prunes, and prunelles are small, averaging about $50,000 from 1910 to 1914, and come principally from Canada. Later statistics

follow:

The rate is 6.67 per cent on the 480,485 pounds that are green, ripe, in brine or dried, and 35 per cent on the remainder, otherwise prepared or preserved.

Of this 5,506,087 pounds, valued at $271,214, were green, ripe, în brine, or dried.

Exports of this group are not separately shown, except for dried prunes.co

PLUSH, HATTERS'. See HATTERS' FUR.
POCKETKNIVES. See KNIVES.

POLES AND POSTS. The most important wood used for posts and poles-about two-thirds of the total-is cedar, including northern white, western red, and southern white. Other woods used are chestnut, oak, pine, cypress, Douglas fir, tamarack, redwood, osage orange, spruce, juniper, hemlock, and locust. Cedar is preferred because of its resistance to decay in the ground. Poles 110572-24- -37

diameters, always specified, vary from 4 to 6 inches in 20 to 30 foot lengths, and from 6 to 10 inches in lengths of 40 feet and over. Poles of metal and concrete and all-metal towers compete with lumber in this field. Underground conduits for wires and trolley systems also serve to reduce the demand for poles.

Western red cedar grows in mixed stands with the Douglas fir in Montana, Idaho, and the Pacific Northwest. Northern Idaho produces more poles than any other region of equal extent. Northern white cedar is found distributed over New England and the Lake States, and furnishes the major portion of cedar poles. Southern white cedar is found along the Atlantic coast. Cypress, with high resistance to decay, is found abundantly in the Gulf States, especially Louisiana and Florida. Competition is active between the regions mentioned. Shipments of western red-cedar poles compete with the northern white-cedar poles of New England and the Lake States in the middle western and eastern markets. In Tennessee, Kentucky, Virginia, and Pennsylvania western chestnut and pine poles, even finding its way to red cedar competes with the locally produced the Southeastern States to compete with the eastern red cedar, cypress, and pine.

The only foreign competition of consequence is with Canada. In British Columbia western red cedar grows in pure stands, making the logging of Douglas-fir trade. The extent of this competition cedar poles less dependent upon conditions in the is affected by the policy of the Provinces of Canada logs. Intermittently these restrictions are prac in imposing restrictions upon the exportation of tically abolished in British Columbia, thus subjectbut tending to the advantage of shingle manuing the logging interest to more active competition, facturers and others using cedar logs.

Production.-An estimate made by the Forest produced at 4,250,000, representing 55,000,000 Service places the number of poles annually board feet of hardwood and 200,000,000 board feet of softwood timber. Poles are quoted per linear foot, according to the length and top diameter. In May, 1921, prices of western red-cedar poles in the Nelson market ran from 43 cents per linear foot for a pole 10 to 20 feet long and 5 inches in diameter at the top to 12 cents per linear foot for a pole 55 to 60 feet long and 8 inches in diameter at the top. Assuming for an average pole a length of 30 feet and a top diameter of 7 inches and a price of 83 cents per linear foot, the total value of the poles produced would be $10,625,000.

Imports of paving posts, railroad ties, and telephone, trolley, electric-light, and telegraph poles (not separately enumerated) in 1914were valued at $409,449. Practically all came from Canada. Later statistics follow: