FLORIDA STRAITS, or NEW BAHAMA CHANNEL. The gulf waters separating Florida from Cuba and the Bahamas, and traversed by the Gulf Stream. The total length is 300 miles, with a width of from 50 to 150 miles. The main channel has been sounded to a depth of over 6,000 feet. FLORIDIA, Sicily, city on the River Ciani, six miles west of Syracuse. Grain, wine and olives are produced in the vicinity. Pop. 12,500. FLORIDSDORF, Austria, a suburb of Vienna, three miles north of that city. It is a thriving industrial centre, with manufactures of locomotives, carriages, chemicals, rubber goods, pottery, hardware, etc. In 1896 it was made the seat of a district. Pop. 38,700. FLORIEP, Robert, German physician: b. Jena 1804; d. 1861. He received his education at the University of Bonn, and after 1833 was connected with the Pathological Museum of the Charité in Berlin. His work 'On the Therapeutic Application of Electro-Magnetism in the Treatment of Paralytic and Rheumatic Affections) (Eng. trans. by R. M. Lawrence 1850) was the most important contribution to electrotherapy of its day. He is also well known for his medical and surgical atlases, the principal of which were 'Chirurgische Kupfertafeln (1820-47); 'Klinische Kupfertafeln' (1828-37); 'Atlas der Hautkrankheiten' (1837) and 'Atlas Anatomicus' (6th ed., 1877). FLORIKIN. See FLORICAN. FLORIN, a coin first struck in Florence in the 13th century. The silver florins of Holland are worth about 40 cents. The British and Austrian florins are each worth 50 cents. The English florin was first coined in 1849. See NUMISMATICS. FLORIO, Caryl. See ROBJOHN, W. J. FLORIO, John, English author: b. London, about 1553; d. Fulham, 1625. His father was a Florentine Protestant, who fled to England to escape persecution. He taught Italian at Oxford and London, having among his pupils several men of note. He achieved repute as a translator and lexicographer. His First Fruits which yield Familiar Speech,' a series of dialogues in English and Italian, appeared in 1578 and was followed in 1580 by an English version of Ramutius' Italian translation of Jacques Cartier's Two Voyages to New France. Encouraged by the success of the former he issued in 1591 a volume of similar nature entitled 'Second Fruits. In 1598 appeared the well-known Italian-English dictionary A World of Words,' dedicated to the Earl of Southampton, and which gave the author wide distinction. In 1601-03 he translated into English Montaigne's 'Essays,' which work was often reprinted. After the accession of James I, Florio became French and Italian tutor to Prince Henry, and later gentleman of the privy chamber and Italian reader to the queen. He was the friend of Shakespeare, Ben Jonson and Sir Francis Bacon, and was pensioned for having made the latter's works known abroad. FLORIS, Frans. See DE VRIENDT, FRANS. FLORISSANT BEDS, a group of sedimentary rocks, occupying the site of a lake, near Florissant, Colorado. The group is famed for its Tertiary fossils. Consult reports of the United States Geological Survey, FLORISTICS. See ECOLOGY; PLANTS, DIS TRIBUTION OF. FLORIZEL, in Shakespeare's 'Winter's Tale,' the Prince of Bohemia, hero of the drama and the lover of Perdita. FLORUS, Roman historian, of the 2d century A.D., probably a native of Spain or Gaul. He is variously styled in the manuscripts; in some L. Annæus Florus, in others L. Julius Florus, in others L. Annæus Seneca and in one simply L. Annæus. He wrote an abridgment (epitome) of Roman history in four books, from the foundation of the city to the first time of closing the Temple of Janus, in the reign of Augustus. His style is florid, and not sufficiently simple for history. The best edition is that of Duker (Leyden 1744); later ones are by Titze (1819) and Seebode (1821). FLOSS SILK, the portions of raveled silk broken off in reeling the silk from the cocoons, carded and spun into a soft untwisted yarn and used for embroidery, etc. See SILK AND SILK INDUSTRY. FLOTATION. See CHEMISTRY, PROGRESS OF; GOLD MINING. FLOTATION PROCESS IN METAL MINING, The. Flotation is a metallurgic process in which valuable metallic minerals are extracted from ores by methods that cause the mineral particles of the pulp to float. A pulp is a mixture of finely crushed ore and water. It has been assumed that this new process is a physical contradiction of the old methods of concentration, in which the force of gravity was the principal factor. Such an interpretation is not permissible because gravity has not been outlawed by flotation; on the contrary the new process is dependent upon the action of the same force. The mineral particles that ascend in the new apparatus are as obedient to gravity as the particles that descend in the old machines. The difference lies in the interplay of molecular forces, notably surface-tension, which is a phase of cohesion, that is, the attraction that binds molecules of like kind to each other. In consequence, the surface of a liquid acts as if it were a stretched membrane or an elastic film. The earliest practicable method of flotation was invented by F. E. Elmore in 1898. It was based directly upon the buoyancy of oil. This is a simple manifestation of gravity, whereby an oil, lighter than water, will rise to the surface of a pulp and carry with it any mineral particles that have become entrained in it. The oil plays the part of a raft or boat. Owing to the small flotative margin offered by common oils, which have a specific gravity of about 0.9 as against the 1 of water, this method involved the use of so much oil that it proved impracticable in metallurgic practice. As first used it required a ton of oil to treat a ton of ore. Next, the direct effect of surface-tension on water was utilized in methods invented in Australia, where they were patented by G. D. Delprat and C. V. Potter in 1902. Such processes come under the heading of film-suspension; they are typified by the floating of a needle on water. In the familiar experiment a small needle is greased, although it will float without the aid of grease. Little or no oil is employed in these processes, which show that bubbles of air entangled in the pulp, or of gas generated therein by the addition of acid, are effective for flotation, Then came the third and much the most important development of this branch of metallurgy. Several investigators, notably, H. L. Sulman and H. F. K. Pickard, made use of the experience obtained in the Australian mills and, in 1904, developed a process in which bubbles of air became the principal agent. This phase of flotation may be called bubble-levitation; it depends upon the attachment of bubbles of air to the metallic minerals in preference to the gangue, such preference representing an affinity or selectiveness that is enhanced by the presence of a small proportion of oil, even less than 1 per cent on the weight of the ore. Whether the result be due to the oiling of the bubble-film or to the oiling of the metallic surface of the mineral particles is not yet clear, but it is recognized that the oil affects the surface-tension of the water of the pulp in such a way as to strengthen the bubble-films and cause the bubbles to last longer. The bursting of a bubble is due to the contractile force of surface-tension, and it must be moderated if the bubble is to last long enough to perform its metallurgic function. The process now in use on a big scale in the United States is one in which a multitude of bubbles, developed in a pulp of ore, is utilized as a means for separating the valuable minerals from the valueless gangue. This separation is based on the fact that sundry minerals (especially sulphides) exhibit a preference for air-bubbles when these are made in a liquid modified for the purpose by the addition of a substance that produces a variable surfacetension. The bubbles result from the dispersion of air in the pulp, whether entrained by agitation or blown through the porous bottom of the vessel in which the operation is conducted. These bubbles rise, and the variable surface-tension produced by the modifying agent added to the water hinders the coalescence of the bubbles while they are rising. The modifying agent may be a constituent of various oils or it may be any one of many other substances, including chlorides of the alkalis; it enters into the bubble-films between water and air, where the mineral particles are caught and held at the interface. The mineral-laden bubbles, arriving at the surface, aggregate into a froth, which is withdrawn, to be collected as a concentrate, which is then drained, filtered, and dried previous to reduction by smelting in the ordinary way. The first successful application of this method in the United States was made by James M. Hyde, in the mill of the Butte & Superior Mining Company, at Butte, Montana, in 1911. This was followed immediately by a suit for infringement of patent brought by the Minerals Separation company, the British corporation owning the Sulman and Picard patents. The litigation is still in progress, after a number of decisions of an indeterminate character, reflecting the lack of scientific knowledge concerning the fundamental physical principles involved in the process. It is even doubtful whether oil is necessary, for experiments have been made indicating that plain sea-water, without an addition-agent, will produce a mineral-bearing froth adequate for the concentration of chalcopyrite in the presence of pyrite and pyrrhotite. This calls to mind the fact that flotation can be made preferential as between minerals by creating conditions that affect some and not others. For example, lead sulphide can be separated from zinc sulphide by a superficial oxidation of the lead in a roasting-furnace without affecting the zinc, so that the latter is amenable to flotation, whereas the former becomes refractory. The cost of operation can be given only in general terms; suffice it to say that the process usually requires no new methods of crushing or of preliminary treatment, but it does demand finer reduction of the ore, say, to 80mesh. Flotation machines are relatively simple and inexpensive, costing about $8 to $12 per ton for a capacity of 200 tons.daily and $4 to $6 per ton for a capacity of 5,000 tons daily. The cost of operating them, including labor, power, and reagents, is about 10 to 15 cents per ton for a 500-ton plant. The oils used are classified as "frothers" and "collectors." The selection of them is empirical. Products of distillation from wood and from coal are used; also petroleum products. The creosotes and kerosene-acid sludge are common agents for froth-flotation. The process is applicable to a remarkable variety of ores, including those of copper, lead, and zinc, as well as those of gold and silver. Apparently minerals having a high metallic lustre are particularly amenable. This includes most of the sulphides of the useful metals and excludes most of their oxides; indeed the presence of oxidized material in the copper ores now being treated is the principal reason for a relatively low recovery, say, 70 per cent, as against the high recovery, say, 90 to 95 per cent, on clean copper sulphides. However, methods for treating the oxidized ores of copper and of lead have been devised, and have been tried on a working scale. The most promising of these are based upon the sulphidizing, or coating of the oxides with a film of artificial sulphide, so as to present a surface suitable for flotation. Hydrogen sulphide is used for this purpose; or the sulphides of calcium and sodium; also sulphur in various combinations. As yet, a sodium sulphide, in 1 per cent solution, has given the best results on oxidized lead ore. The process has an application as much wider than that of cyanidation as cyanidation was more comprehensive than chlorination. About 30,000,000 tons of ore are being treated annually by flotation in the United States, and as soon as the embargo of royalty or of litigation is lifted from the process there should be an extension of its usefulness in this and in other countries. A large body of technical literature has grown around the subject during the last three years. The principal textbooks are Hoover, Theodore J., Concentrating Ores by Flotation, (1912); Rickard, T. A., 'The Flotation Process' (1916); Rickard, T. A., and Ralston, O. C., FLOTOW, Friedrich (frēd'riн flō'to) von, German musical composer: b. Teutendorf, Mecklenburg-Schwerin, 27 27 April 1812; d. Wiesbaden, 24 Jan. 1883. His earlier operas (which include one called 'Rob Roy') did not find favor among the Parisian opera house directors, so he had to content himself with performances in the private theatres of the aristocracy. This brought him gradually into notice, however, and his 'Naufrage de la Méduse' was publicly produced in 1839. Alessandro Stradello' was first performed at Hamburg in 1844 and his most successful opera, Martha, was originally given at Vienna in 1847. His subsequent works, such as Indra' (1852), 'Rübezahl (1854); Albin' (1856); L'Ombre' (1869), achieved but small success. He was elected to the French Institute in 1864. FLOTSAM, JETSAM, and LIGAN, in law, flotsam, or floatsam, is derelict or shipwrecked goods floating on the sea; jetsam, goods thrown overboard which sink and remain under water; and ligan, goods sunk with a wreck or attached to a buoy, as a mark of ownership. When found such goods may be returned to the owner if he appear; if not, in England, they are the property of the Crown. See DERELICT; SALVAGE. FLOUNDER, any of several of the more common and useful flat fishes (q.v.) of northern waters. There are at least 500 species. The commonest American species are the "summer" and "winter» flounders. The latter (Pseudopleuronectes americanus) is dark rusty brown, more or less spotted, about 15 inches long when mature and weighs one to two pounds. It is caught in the colder months from Chesapeake Bay to Labrador, and is excellent eating. The "summer"> flounder (Paralichthys dentatus) becomes twice as large, is light olive brown, studded, when adult, with numerous small white spots and is esteemed for the table. The "four-spotted" flounder (P. oblongus) and the Gulf species (P. albiguttus) are closely related. On the Pacific coast several good species are known; and the British coast has a valuable species in Pleuronectes flesus, closely resembling the plaice (q.v.). The halibut (q.v.) is closely related and the turbot (q.v.). Consult Jordan, 'Guide to the Study of Fishes' (1905). See FLUKE; FISH. FLOUR. See FLOUR, WHEAT. FLOUR, Wheat, a finely ground and bolted product used for food. Ordinary white or bread flour, of which there are a number of grades, is composed of the interior portion of the wheat kernel subjected to processes of pulverization and purification. In the preparation of white flour either the major portion or all of the bran, germ and other offal parts are removed. When the entire wheat kernel is ground into a meal, it is called graham flour. When a portion of the bran is removed the product is usually called purified graham or entire wheat flour. The history of wheat milling shows that many and gradual changes have taken place since the early times when wheat was pulverized between stones to the present time when it is reduced by steel rolls. Wheat has variously been reduced to flour by means of stone crushers, saddle stones and stone mortars. The ancient Greeks, Romans, Chaldæans and Egyptians used saddle stones for grinding wheat into flour, the wheat being placed in a concave stone and rubbed with a convex stone rocked backward and forward. Saddle stones are still in use among the native Africans, and are known to have been used from earliest times. They are also found among the remains of the prehistoric Swiss lake-dwellers and mention is made of them in the earliest literature. Their use appears to have been common among all primitive races and they are in use to-day by many barbarous and halfcivilized nations. Near the beginning of the Christian era, querns or crude crushers in which the parts were fitted mechanically came into use. The upper stone or pestle revolved upon the lower concave stone. The quern was the forerunner of the millstone. Querns are still in use in some Asiatic and European countries. The millstone came into use about the 14th century and was the result of gradual evolution from the stones shaped by nature and operated by hand to specially hewn and dressed millstones propelled by various forms of motive power. In ancient times, flour was prepared in each household, the grinding being done by women, slaves and menials. During the Middle Ages when the feudal system was at its height, crude flour-mills or querns formed a part of the outfit of each castle or estate. In some countries, the right to operate these mills was vested in the clergy, and in early English history frequent mention is made of contests between the people and the landlords and clergy relative to their right to operate these mills or querns. Until the beginning of the 17th century wheat milling was simply a crude agricultural industry, the earlier mills being operated by slaves, then by oxen. Later water wheels and windmills were used as motive power. About 1820, a flour-mill was first operated by steam. Bolting cloths for removal of the bran have been in use for about two centuries. About 1870 the present roller process of flour production was introduced from Hungary into America. The process consists of the gradual reduction or pulverization of the floury portions of the wheat kernel between corrugated and smooth steel rolls and of the purification of the product by means of aspirators. During the process of milling, the granular middlings undergo gradual reduction and are passed from roll to roll. At each break or grinding, the fine flour is removed by bolting, the middlings are separated and passed to other rolls and the tailings are subjected to further reduction. Before passing to the rolls, the wheat is screened to remove loose dirt and weed seeds and occasionally washed to remove adhering dirt and debris; then dried or tempered with steam, as may be necessary in order to more easily effect reduction. The first break simply flattens the kernels after splitting them in halves along the longitudinal groove. The germ is pinched off by the rolls and is readily separated. The flour passes automatically from one break or set of rolls o another. Each break is regulated so as to pulverize a little finer than the preceding one. Each middlings stream is purified by passing through the middlings purifier, suction being applied to remove the fine dust and dirt. Finally the various streams are blended so as to form different grades of flour. In large mills, the cleaned wheat is usually elevated to the top of the mill and then passed on to the rolls, and the various resultant flour streams blended in such a way that the final flour product is obtained after being separated into 40 or more separate streams. In or The introduction of the roller process of milling has made it possible to use varieties of wheat from which high-grade flour_could not be made by the old stone process. By the roller process of reduction a portion of the hard granual middlings which were formerly excluded from the flour and sold with the byproduct used for animal feeding are now reduced and added to the patent grades of flour. About 75 per cent of the cleaned wheat is returned as merchantable flour, 72 per cent_being straight grade or ordinary white flour. dinary milling, the grades are as follows: (1) patents; (2) straight, sometimes called standard patent; (3) first clear: (4) second clear. Patent flour is the highest grade manufactured. Its gluten has greater power of expansion and absorbs more water than that from any other grade. Patent flour produces the whitest and largest sized loaf of bread. Straight or standard patent flour is similar to the patent, but the bread is slightly darker in color and the gluten does not possess quite so high a power of expansion. First clear grade flour is obtained after the removal of the first patent grades. This flour is slightly darker. in color and produces a less pleasing loaf than the patent grades. Second clear or low grade is the name given to a small amount of four obtained after the removal of the first clear. In some mills about 12 per cent of the cleaned wheat is recovered as first clear flour and about 5 per cent as second clear or low grade. When the wheat is milled so that the patents and the first clear are all obtained as one flour, the product is called straight grade. This is the flour that is extensively used for bread-making purposes. Straight flour is the sum of the patents and the first clear. The lowest grade of flour manufactured is called red dog; it is dark in color and possesses but little power of expansion. It is secured largely from those portions of the wheat kernel adjacent to the germ and aleurone layers. Red dog flour is not generally used for human food, but is employed in the arts, for the feeding of animals and occasionally in the preparation of some cereal breakfast food. It has a high per cent of protein or nitrogenous material, but is not valuable for bread-making purposes because the gliadin and glutenin (see BREAD AND BREAD MAKING) are not present in the right proportions to form a balanced gluten. By blending the different streams of flour, various commerical grades sold under different trade names are secured. The composition and properties of different kinds of flour result from the kind of wheat used in preparation (see WHEAT) and the method of milling employed. By the roller process of milling, the germ is excluded because of its poor bread-making properties and its fermentable nature. The wheat offals of which shorts and bran form the main portion are by-products used for the feeding of animals. About 25 per cent of the cleaned wheat finds its way into the offals. Bran is the episperm or outer covering of the wheat kernel. As human food, it is indigestible and does not yield as large an amount of available nutrients as the floury part of the wheat kernel. As an animal food, however, it has a high value. Shorts consist mainly of the fine bran mixed with some of the floury portions of the wheat kernel. When the wheat screenings, consisting of weed seeds and other refuse, are ground and mixed with the offal, the product is known as bran or middlings, with ground screenings. From 1.3 to 1.6 per cent of the weight of the cleaned wheat is recovered as germ. Wheat flour is composed of starch, gluten proteins, water, fat, ash, or mineral matter and small amounts of other compounds, as sugars, cellulose, organic acids, amids, etc. The proximate composition of the different kinds of flour when milled from the same lot of hard wheat is given in the following table: (The two types of patent flour be milled at the same Water, Per Cent time). could not Wheat. 8.50 12.65 2.36 74.69 1.80 0.75 0.18 4.140 Special patent flour.. 10.55 11.08 1.15 76.85 .37 .15 Patent flour. 10.49 11.14 1.20 76.75 44 .17 Straight flour 10.54 11.99 1.61 75.36 .50 .20 First clear grade. Second clear grade. Red dog flour Shorts, middlings. Bran.. 10.13 13.74 2.20 73.13 .80 .34 .124.097 10.08 15.03 3.77 69.37 1.75 .56 .27 4.267 9.17 18.98 7.00 61.37 3.48 8.73 14.87 6.37 65.47 4.56 9.99 14.02 4.39 65.54 6.06 2.20 .59 4.485 144.414 .23 4.198 From the table, it will be observed that there is a gradual increase in the amount of ash, proteins and fat from the first patent flour to the red dog or lowest grade of flour. In fact, the variations in ash content of the different * Straight_grade flour is composed of first and second patents and first clear grade. grades of flour are so regular that the percentage of ash can, at times, be taken as an index to the grade of flour. The highest grade flours, as first patent, contain least ash because of the more perfect exclusion of the bran and endosperm parts. In the straight grade or ordinary bread flour, there is only from 6 to 7 per cent less nitrogenous material as proteins than in the wheat from which it was milled. Second clear and red dog flours contain a large amount of protein, fat and ash, and judged by their proximate composition only, would appear to have a higher nutritive value than the patents or straight grade flours. But when judged on the basis of digestibility, available nutrients and physical character of the bread, these flours are found to have a much lower value than the patents or straight grade flours. (For nutritive values, see article on BREAD AND BREAD MAKING). During the process of milling, the flour particles pass through bolting cloths containing from 12,000 to 16,000 meshes per square inch, which results in even and fine granulation of the flour particles. The character of the flour particles as angular or spherical depends largely upon the character of the wheat as hard or soft, and to a less extent upon the method of milling. The flour granules from hard wheat are angular and have a sharp feeling akin to fine sand, while soft wheat flours produce small spherical particles lacking in gritty feeling. Flours made from strong hard glutinous wheats contain more protein and have a higher food value than those made from soft starchy wheats. In the testing of flour, particular attention is given to physical characteristics, as color, purity as indicated by absence of dirt and fine pieces of bran, capacity to absorb water, quality of gluten and character of the bread product. For bread-making purposes, the quality of the flour depends largely upon the amount and quality of the gluten. The gluten is obtained by making a stiff dough of the flour and then washing this dough with an abundance of water, which removes the starch, leaving the gluten in the form of a gum-like mass. Gluten from high-grade flours is firm, elastic, white or of slightly yellowish tinge and possesscs good qualities of expansion. Poor gluten is dark in color, sticky and lacking in elasticity. The color of the flour depends largely upon the quality of the wheat and the method of milling employed. Some wheats produce creamy or yellowish flours, others chalk white flours and others dark-colored flours. Dark-colored flours, however, produce bread of inferior quality, creamy and white flours producing the best grades of bread. The granulation of the flour is also taken as an index of its quality, as it reveals to the experienced miller and baker the character of the flour. Comparative baking tests are generally resorted to in order to determine the bread-making value of flours. By these tests, under uniform conditions with the same amount of flour, yeast, water, etc., in each case, differences in the bread-making qualities of the flour are readily revealed. When flour is stored for a long time, it sometimes becomes inferior through fermentation. Ordinarily, flour will not deteriorate until after it has been kept for many months or more. Some wheats produce flours of better keeping qualities than do others. The soundness of the wheat, as freedom from rust, smut or other blemishes, influences the keeping qualities of flour as well as does also the process of milling, particularly the extent to which the cleaning and purification are perfected. Wheat flour is not ordinarily adulterated, although at times attempts have been made to add other cereals and mineral adulterants. The national flour law requiring all mixed flours to be branded and to pay a slight revenue tax has prevented extensive adulteration. At one time, corn flour produced by milling corn was used for adulterating wheat flour. This, however, was only practised for a very short time when corn was cheap and wheat was high in price. The blending of wheat and corn flours has never proven succes ful as an inferior bread product results, and the practice since the passing of the national flour law has been discontinued. Wheat flour appears to be less subject to adulteration than many other articles of food. See ADULTERATION. Wheat flour is used not only for bread making but for other purposes. Crackers, cakes, pastry and many food articles are made largely of flour. Flour is also used in the arts and industries and in various manufacturing operations. The comparative value of bread made from different kinds of flour, as graham, entire wheat and straight, is discussed in the article BREAD AND BREAD MAKING. As a conservation measure during the war with Germany, the United States Food Administration requested that 100 pounds of standard wheat should be milled so as to produce not less than 744 pounds of flour; the residue, about 25 pounds, consisted of wheat byproducts, the flour milled in accord with the United States Food Administration regulations being designated 100 per cent flour; no separations in patent and clear grades being made. One hundred per cent flour, comprising all the flour separated from the wheat, is about a 75 per cent extraction (not less than 744), that is it represents about 75 per cent of the wheat milled. This flour should not be confused with 100 per cent extraction flour, which is a graham flour. The 100 per cent flour contains no bran or wheat by-products, while the 100 per cent extraction flour contains all the bran and byproducts of the wheat. To make the short wheat crop of 1917 go as far as possible in bread-making, bakers were required to mix from 20 to 25 per cent of other flours as corn flour, barley flour or oat flour with the wheat flour used. By this and other means a large amount of wheat and flour was made available for export to other countries at war with Germany, and also to neutral countries. It is estimated that four and a half bushels of wheat, equivalent to about 200 pounds of flour, are consumed annually per capita in the United States. More flour is consumed in the Northern than in the Southern States. The consumption of flour as food has, during recent years, gradually increased. Some political. economists and scientists have feared that at no distant date the consumption of flour would exceed the production of wheat. But improved methods of agriculture and the opening up of large tracts of land suitable for wheat culture, as in northwestern Canada, render this improbable. From earliest times wheat and wheat |