Page images



Phosphine. CuHjgNiO,. Diamidophenylacridinehydrcehloride; by-product in fuchsine making; orange powder, soluble in water. It dyes cotton yellow upon a tannin mordant, and is not to be confounded with the gaseous phosphine, PH>. See Phosfhureted Hydrogen.

Phosphine*. Compounds formed by replacing the hydrogen of phosphoreted hydrogen (PH,) by organic groups or radicals. Examples: PH3.CH,.. methyl phosphine. PH:(CaH6)„ diethyl phosphine.

Phosphites. Derivatives of phosphorus acid.

Phosphomolybdates. Metallic derivatives of phosphomolybdic acid.

Phosphomolybdic Acid. Various in composition; the ordinary form has theformulaHaPOj.HMoOa-l-^HjO. Ammonium phosphomolybdate is its most important derivative.

Phosphonium Bromide. PH,Br. Colorless, transparent cubes, very hygroscopic; unstable; made by treating phosphine with gaseous hydrobromic acid.

Phosphonium Cbloride. PH .01. Small lustrous needles, obtained by subjecting equal volumes of phosphine and hydrochloric acid gas to 2.7 atmospheres pressure at 2.2° C.; more unstable than the corresponding bromide or iodide.

Phosphonium Iodide. PH,I. Transparent cubes, formed by the action of phosphine on hydriodic acid.

Phosphor Bronze. Alloy more resistant to abrasion than the ordinary bronzes for bearings and journal brasses, and more infusible after being cast for tuyeres and other such uses, made by fluxing bronze with phosphorus, and containing less than one per cent of this. Invented by a Belgian engineer 1870. See Copper, Metallurgy Of.

Phosphorescence. Power in certain substances of appearing self-luminous when viewed in the dark, after being exposed for a time to the action of any luminous radiation. The phenomenon is supposed to be due chiefly to the action of rays of rather high refrangibility. The sulphides of calcium and of barium are notably phosphorescent. In many cases the phosphorescence is of short duration; for the examination of


Becquerel's Phosphoroscope

such Becquerel's phosphoroscope may be employed. This consists of a device by which in rapid succession a phosphorescent body is exposed to bright light and brought against a dark background before the eye of an observer situated in darkness. Most substances are found to be phosphorescent when examined in this way. The rays of light which generate phosphorescence are called phosphorogenic rays.

Phosphorescent Clouds. Very delicate, silver-white clouds, seen in Europe in June and July, even at midnight, during the short nights. Simultaneous photographs show that these are from 10 to 15 m. high and probably shine by reflecting distant twilights.

Phosphorescent Organs. Present on the ventral side of the abdominal segments, and sometimes in other parts of the body of insects; also on the sides of deep-sea fishes. The cells of these organs produce light under nervous stimulation of a trophic character. Examples are glow-worm, fire-fly and certain marine animals.

Phosphoreted Hydrogen, or Phosphine. PH3. Sp. gr. 1.2. It was discovered by Gengembre 1789. Ignes fatui is

thought to be due to it. Poisonous, colorless, slightly soluble gas, of an unpleasant, garlic-like odor, usually spontaneously inflammable; made by heating phosphorus in a solution of caustic potash. It does not take fire in the air when pune. Liquid phosphine has the formula PaH)( and solid phosphine P»Ha.

Phosphoric Acid, or Orthophosphoric Acid. HaPO,. The anhydrous acid consists of hard, colorless prisms, which rapidly absorb moisture from the air, forming a thick liquid. It is made by dissolving phosphorus pentoxide in hot water, or by treating phosphorus with nitric acid; it is tribasic, yielding primary, secondary, and tertiary salts by replacement of one, two, and three hydrogen atoms respectively. Glacial phosphoric acid is the more common commercial form: it is Metaphosphoric Acid (q.V.). When heated to 200°-300°C, it is converted into pyrophosphoric acid; heated to 400° C, it yields metaphosphoric acid.

Phosphorite. Fibrous, massive, or concretionary forms of Apatite (q.v.).

Phosphorogenic Rays. See Phosphorescence.

Phosphoroscope. See Phosphorescence.

Phosphorous Acid. H3POs. Transparent crystals, made by treating phosphorus trichloride with water; converted into phosphoric acid by heat; dibasic acid.

Phosphor Tin. Brittle, white substance, composed of tin and phosphorus in varying proportions; sp. gr. 6.56; soluble in hydrochloric acid; made by throwing phosphorus upon melted tin, or by melting equal parts of tin and phosphorus pentoxide together; used in making phosphor bronze.

Phosphorus. P. At. wt. 31, sp. gr. 1.83, sp. ht. .202, mpt. (under water)44° C, bpt. 290°C,valenceHL,V. Discovered by Brand 1669; waxy, transparent, yellow substance. It does not occur in nature, on account of its great affinity for oxygen; on exposure to the air at ordinary temperatures it takes fire. It is made by calcining bones, then treating with sulphuric acid, when this reaction takes place: Ca3(P01)a + 2H,SOi = CaH, (PO<), + 2CaSO(. This primary phosphate is heated and converted into the metaphosphate. CaH,(PO«), — Ca(POs)3


Distillation of FhosphoruB.

4- 2H30. It is then distilled with carbon and silica, and condensed under water. 2Ca(PO,), + 10C + 2SiO„ — 4P + 10CO + 2CaSiO,. When taken into the stomach, it is poisonous, as are its vapors. It must be handled with the greatest care, since it takes fire readily and causes serious wounds. It occurs in several allotropic forms. See Phosphorus. Amorphous, and Phosphorus, Crystallized. It is insoluble in water, but soluble in carbon disulphide. It is used in making matches and as a poison for vermin.

Phosphorus, Amorphous. Made by heating ordinary phosphorus to 300° in a sealed tube; dark red powder, insoluble in carbon disulphide. It does not emit light, and is not poisonous. Heated to 261° C. it is converted into the ordinary variety. It is used for making safety matches, being applied to the box.

Phosphorus, Crystallized. Metallic phosphorus. If ordinary phosphorus is heated with lead for ten hours in a sealed tube from which the air has been exhausted, on cooling, black crystals are found. They undergo no change in the air.

Phosphorus Hydrides. See Phosphoreted Hydrogen.

Phosphorus Otj chloride. POC1,. Clear, fuming liquid, made by treating phosphorus pentachloride with hvdroxyl compounds. Treated with water it yields phosphoric and hydrochloric acids.

Phosphorus Pentabromidc. PBrs. Yellow, crystal1174


line solid, made by adding bromine slowly to phosphorus tribromide.

Phosphorus Pentachlorlde. PC1>. Solid, crystalline, yellowish, fuming compound, made by treating phosphorus trichloride with chlorine. It sublimes without fusion. It is used as a reagent for testing for the presence of hydroxyl and for introducing chlorine into hydroxyl compounds.

Phosphorus Pentafluorlde. PFI6. Colorless, strongly fuming gas, with a marked odor; made from arsenic trifluoride and phosphorus pentachloride.

Phosphorus Pcntaselenlde. PSe,. Dark-red, glassy substance, crystallizing from carbon tetrachloride in black needles, decomposing in moist air; made by heating phosphorus and selenium in a carbon dioxide atmosphere.

Phosphorus Pentasulphide. PjSt. Grayish-yellow crystalline mass, or thin, almost colorless crystals; mpt. 274°276° C, bpt. 530° C.; soluble in caustic alkalies and ammonium hydroxide: made by heating phosphorus (2 at.) and sulphur (5 at.) together in an atmosphere of carbon dioxide.

Phosphorus Pentoxide. P,05. Phosphoric anhydride; white powder, becoming glassy on fusion; odorless, with a strong acid taste, sublimable; extremely hygroscopic, therefore used extensively as a dehydrating agent; formed by burning phosphorus in a free supply of air or in oxygen; very soluble in water, forming Phosphoric Acid (q.v.).

Phosphorus Sulphobromidc. See Phosphorus Sul


Phosphorus Sulphochloride. PSCU. Colorless, strongly refractive, mobile, fuming liquid of unpleasant odor. It dissolves sulphur and phosphorus. It is made by heating phosphorus with sulphur monochloride, S,Cla. The corresponding bromine and fluorine products are very similar in properties and are made in the same general way.

Phosphorus Sulphofluoride. See Phosphorus SulPhochloride.

Phosphorus Trlbromidc. PBrs. Colorless liquid; bpt. 175° C., sp. gr. 2.7; made by treating phosphorus with bromine; used in the synthesis of organic compounds.

Phosphorus Trichloride. PCI,. Fuming, colorless liquid, of a sharp, penetrating odor; sp. gr. 1.61; made by passing chlorine over gently heated phosphorus; decomposed by water, forming hydrochloric and phosphorus acids; used as a reagent for testing for hydroxyl.

Phosphorus Trifluoride. PR,. Colorless, non-fuming gas, decomposes with water into phosphorous and hydrofluoric acids; made by heating copper phosphide, CuaP,, with lead fluoride.

Phosphorus Trliodide. PI>. Red crystals; mpt. 55° C; made by treating phosphorus with iodine; used in the synthesis of organic compounds.

Phosphorus Trloxlde. P,0, or P.O.. Phosphorus anhydride; white, voluminous, easily volatile substance of a garlic-like odor and acid taste, obtained in large crystals by sublimation in a vacuum; mpt. 22.5° C. The action of light causes it to change rapidly to yellow and finally red. It is formed by the incomplete combustion of phosphorus in air.

Phosphorus Trlselenldc. PSe,. Similar to the trisulphide; robin-red solid, taking fire in the air. soluble in caustic potash; made by fusing phosphorus with sulphur.

Phosphorus Trisulphide. PjSj. Grayish-yellow, crystalline substance; mpt. 167° C.; soluble in caustic alkalies and ammonium hydroxide; made by heating phosphorus and sulphur together in an atmosphere of carbon dioxide.

Photantityplmeter. Form of actinometer introduced by Marchand 1860, in which the solar radiation falls upon a quantity of chemicals and causes a slow disengagement of carbonic acid gas, whose volume is an index of the power of the solar rays.

Photius, d. ab.891. Patriarch of Constantinople 861; great scholar, whose extensive works upon ancient literature, lexicography, and ecclesiastical history are of value, as rescuing from oblivion names and facts which would otherwise have perished in the destruction of the libraries of Constantinople and the East. He was involved in violent quarrels with Rome, and was deposed 867 and 886.

Photochromoscopc. Instrument invented by F. E. Ives for viewing specially prepared photographs, known as chromograms, in such a way as to reproduce perfectly all the colors of the original object. The Ives method consists, first, of a reproduction, in a special camera, of a photograph consisting of three distinct images, which, by the differences in their light and shade, constitute a color record, each image, in fact, representing one of the three fundamental color sensations, red, green, or blue-violet; and second, of viewing this triple

photograph in the photochromoscope, which is practically a reversal of the camera, and blends the three images into one so perfectly that one seems to be viewing the object itself.

Photo-Engraving. From a silver collodion negative a gelatin positive is made, from which a bitumen mold on glass is prepared. From the latter a plaster-of-Paris mold is made, in which type-metal is cast. From this impressions in ink on paper are made. This is the Moss method. Another process, more commonly used, is to expose to the light a gelatin plate, sensitized with potassium bichromate, beneath a collodion negative. The unaffected gelatin is dissolved by water and the film transferred to a polished zinc or copper plate, which is then treated with an etching liquid, the former with nitric acid, the latter with perchloride of iron. The film is also produced directly upon the metal plate. It is also produced by exposing to the light, under a silver negative, a plate coated with bitumen, the unaffected bitumen being dissolved by turpentine. In these processes, the silver negative is made from a line drawing. When a picture with gradation of color is to be reproduced, a transparent screen, with network of black lines upon it, is interposed between the negative and the sensitized plate, upon which fine dots are thus produced. This is the half-tone process. See Photogravure.

Photographic Object-Glass. Object-glass so formed as to bring the actinic rays of the spectrum to a common focus, instead of the visual rays.

Photographic Survey Of The Heavens. April 16. 1887, by invitation of Admiral Mouchez, an international congress assembled at Paris for the purpose of considering plans for a photographic survey of the entire heavens on a uniform system. The scheme then inaugurated involved apportioning the work among different observatories, the construction of special instruments, and the settlement of innumerable questions of detail, to insure uniformity. All this required time; the work is now fairly under way, out many years will be required for its completion. Two distinct series of plates are to


Equatorial Photographic Telescope at Melbourne Observatory, be taken: 1, a series with sufficiently long exposure to show all stars to the 11th magnitude inclusive, for the formation of a catalogue; 2, a series with long exposure, 40 minutes, for purposes of a chart. The work has been distributed among 18 observatories, but does not include a single observatory ol the U. S. On the other hand, an independent photographic survey is being conducted at the Harvard College Observatory with a splendid instrument of 24 in. aperture, the intention being to obtain with this single instrument a chart of the entire heavens.

Photography. Art of producing pictures by light on sensitized surfaces. In 1802 Wedgwood, in England, on paper moistened with a solution of silver nitrate, reproduced a design on translucent paper laid upon it and exposed to light. Davy found that silver chloride was more sensitive. In 1814 Niepce discovered that an asphaltum film on metal or glass, exposed to light under a drawinsr, was rendered insoluble in oil of lavender and petroleum. He thus produced pictures in 1175


a camera obscura which he named Heliographs. He became associated with Daguerre 1829. The latter, in 1839, invented the Daguerreotype (q. V.). The Callotype was patented by W. H. Fox Talbot 1841. Paper sensitized with silver iodide, after exposure in a camera, was developed by silver nitrate and gallic acid, the unaffected silver salt being removed by sodium thiosulphate, a suggestion of Sir John Herschel. The paper was then waxed to render it translucent, and constituted a negative, which was exposed to light upon similarly prepared paper to produce a positive. Sir John Herschel suggested the use of glass plates. Niepce Saint-Victor introduced the use of egg albumen containing the silver salts for coating glass negatives and paper positives.

The collodion process was invented by Scott Archer of England 1851. Pyroxyline is dissolved in alcohol and ether, containing cadmium and potassium iodides, and with this a glass plate is coated. This is dipped in a water solution of silver nitrate, which produces silver iodide in the film. After exposure in the camera, the picture is developed by a solution of ferrous sulphate or pyrogallic acid which causes a deposition of metallic silver where the light has acted, thus producing a negative. The unaffected silver salts are removed by a water solution of sodium thiosulphate. The paper for the positives contains salt and is sensitized with nitrate of silver, producing silver chloride. This is exposed to the light under the negative, which reduces the silver salts to metallic silver, producing a positive. This is toned or colored in a water solution of gold chloride, the unaltered silver salts dissolved by sodium thiosulphite and thoroughly washed.

The gelatin dry plates are made of an emulsion of gelatin in water, with silver chloride, bromide, or iodide, dried upon glass plates. The emulsion was used successfully 1871 and the dry plates ab.1878. They are used and treated similarly to the collodion plates. Orthochromatic and isochromatic gelatin dry plates contain small quantities of eosin or other coal-tar dyes and reproduce the true shade relations of colors; they were first made by Vogel 1873.

Color photography, reproducing colors, has not yet been effected; Gabriel Lippman of Paris claimed to have accomplished this in 1891, but no valuable results have been obtained.

Color printing has been accomplished by plates made by interposition of a red, green, or blue-violet screen in the camera, which permits the passage of the respective rays. By superprinting with the respective pigments the original colors can be obtained. See Ferrotype, Blue-printing and Platinotype.

Ambrotype.—This is silver negative on glass with a black background of paper or cloth.

Artotype.—A glass plate is coated with albumen and potassium bichromate, dried at 110° F., and the albumen rendered insoluble by exposure to light. It is then coated with gelatin and potassium bichromate, dried at 110° F., and coated with

felatin, isinglass and ammonium bichromate, with a small adition of chrome alum and potassium bicarbonate, and dried as before. The plate is then exposed under the negative, by which the transmitted light renders the gelatin insoluble, ft is now immersed in water to remove the unaltered bichromates. Paper prints are made from this in the lithographic press, the ink adhering only to the altered gelatin. Two thousand impressions have been taken from a plate. This process was perfected by Joseph Albert of Munich, and is sometimes called the Heliotype, Photogelatin, and Albertype (q.v.).

Photogravure. In making a plate for this process, a silver collodion positive on glass is made from a silver collodion negative on glass. A gelatin film, containing lampblack and sensitized with potassium bichromate, on tissue paper, is exposed to the light under the positive. The resulting negative is laid, face downward, on a copper plate, coated with rosin, and the paper stripped off, leaving the gelatin film attached to the copper plate. This is treated with hot water, which dissolves the gelatin which has not been affected by the light, leaving a gelatin negative on the plate. This is then treated with perchloride of iron, which etches the copper, more or less, according to the thickness of the gelatin, thus reproducing a positive on the copper. This is frequently finished by handwork and then steel faced by an iron solution to increase its durability. Prints are made on paper from this in a copperplate press.

Photolithography. A film of bichromatized gelatin on paper is exposed to light under a negative and the unaltered bichromate washed out with water. The film is then inked with greasy printers' ink, which adheres only to the gelatin rendered insoluble by light. This is laid face downward on the lithographic stone, upon which it is pressed, thus transferring the ink to the stone. The paper is removed by rubbing with water. A water solution of gum arabic fills the pores of the uninked stone. The picture in ink is thus left upon the stone to which printers' ink adheres and may be transferred to paper in the press.

Photo-Mechanical Printing (woodburytype). A layer of gelatin sensitized with potassium bichromate is exposed under a negative and the unaltered gelatin dissolved in warm water, leaving a gelatin relief. This is impressed in a sheet of lead, thus forming a mold. This is filled with colored gelatin, covered with paper and a glass plate and pressed. The gelatin cast adheres to the paper and is hardened by alum solution. The Stannotype, also invented by Woodbury, is made in a similar manner, a carbon gelatin mold being lined with tinfoil. In the Phototype, Heliotype and Collotype processes the gelatin relief is printed from with printers' ink" See AUTOTYPE.

Photometer. Instrument for comparing the illuminating powers of two sources of light. The two lights are placed at such distances from the illuminated surface .'is to produce the same effect, as judged by the eye. In Rumford's photometer a vertical rod casts two shadows on a screen; the distances are so adjusted that the illumination of these shadows shall be


Rumford's Photometer.

equal; the illuminating powers of the sources are then proportional to the squares of their distances from the screen. In Bunsen's the sources of light are placed at such distances on opposite sides of a translucent disk, having on it a paraffined spot, that the illumination, as viewed from each side successively, appears to be the same. The same law of distance applies in this case also.

Photometer, Meridian. Designed by Pickering. The instrument is mounted in the meridian with appliances so arranged that the light of each star as it culminates may be compared with that of Polaris.

Photometer, Polarizing. The light is passed through a Nicol's prism with apparatus so arranged that by turning the prism the light may be reduced to the same brightness shown by a standard star in the same field. The latter may be a real star or an artificial one.

Photometer, Wedge. The important feature is a wedge of colored or neutral-tinted glass: the star's light is measured by the thickness of the wedge necessary to extinguish it.

Photometry. Science of measuring and comparing the relative amount of light emitted by different sources. The methods generally consist in measuring the distances at which two sources produce equal intensities of illumination. Hence by the application of the law of inverse squares the ratio of the quantities of light emitted can be determined. The unit in photometric measurement is the quantity of light emitted by a standard candle. This is a spermaceti candle, six to the pound, each burning 120 grains per hour. The Paris Electrical Standards committee in 1884 recommended as the unit the light emitted by one square centimeter of melted platinum at its temperature of solidification.

Photometry, Stellar. Measurements of the amounts of light, or relative brightness, of stars.

Photonephograph. Apparatus (consisting essentially of twin cameras adjustable at any angle of elevation and azimuth) for taking simultaneous photographs of a cloud as seen from two points on the earth; so named by Abney 1883.

Photophone. Crystalline selenium when acted upon by light increases in electric conductivity, sometimes even tenfold. Light of varying intensity produces corresponding changes of conductivity. The photophone is constructed on this principle.

Photosphere Of The Sun. Luminous mass which forms the visible disk. It consists of a mass of luminous clouds floating in the sun's atmosphere.

Phototaehy, Metrical. Method of determining the sun's distance by direct measurement of the velocity of light, and of the time which it requires to pass from the sun to the earth.

[blocks in formation]

Phototaxls. Habit of certain organisms of placing themselves in definite positions with reference to the incident rays of light, as in the zoospores of some Alga.

Phototonic. Action of light upon certain plants, increasing or inducing irritability.

Photozincograph. See Photo-engraving.

Pliragma. Membrane stretched across the hollow stems of the Equisetacece at each node; also dissepiments of certain fruits.

Phragmacone. Chambered portion of the internal shell Of a BELEMNITE (q.v.).

Phranza, George, 1401-1478. Byzantine historian. His Chronicon, written after the fall of Constantinople and pub. 1796, extends 1359-1477.

Phrenology. So-called system of psychology, founded by Gall (q.v.) and developed by his followers. At one time it had considerable popularity, but has now fallen into disrepute. It was based upon four principles: 1. Tha brain is the organ of mind. 2. The mental powers can be analyzed into a definite number of independent faculties. 3. These faculties are innate, and each has its seat in a definite region of the brain. 4. The size of each of these regions is proportionate to the power of manifesting the faculty associated with it. Gall divided mind into 26 faculties, and mapped out a corresponding number of ■areas on the skull: this number was varied by succeeding



I. Propensities.—1. Amativeness: 2. Phuoprogenitiveness; 8. Inhabitireness or Concentrativeness; 4. Adhesiveness: ft Combativeness; 6. Destructiveness and Alimentiveness; 7. Secretiveness; 8. Acquisitiveness; 9. ConBtrnctiveness. II. Shntimsnts. —10. Self-esteem: 11. Love of Approbation; 12. Cautiousness; 13. Benevolence; 14. Veneration; 15 Firmness; 16. Conscientiousness; IT. Hope; 18. Wonder; 19. Ideality; 20. Wit; 21. Imitation.


I. Perceptive.—22. Individuality; 23. Form; 24. Size; 25. Weight; 28. Coloring; 27. Locality; 28. Number; «). Order; 30. Eventuality; 31. Time; 32. Tune; 33. Language. II. Reflective.— 34. Comparison; 35. Causality.

phrenologists, the maximum number of faculties and areas, 43, being reached by Fowler of New York. The objections to this system are many and unanswerable. Psychologically, the division of mind into a number of independent faculties is admittedly impossible, while the mapping out of sharply defined areas of the brain which can be determined by external examination of the skull has been shown by the modern researches in brain physiology to be in direct opposition to the facts. At the same time there is localization of brain function, and Gall's system of phrenology must be given the credit of being the first systematic attempt on empirical lines to determine its details.

Phryganidae. See Trichoptera.

Phrygia. Region of central Asia Minor, whose limits varied at different times. The original inhabitants were probably Thracian. The earliest Greek music came in part hence.

Phrygian Language. Only known by glosses and inscriptions, and was probably an Indo-European tongue, closely related to the Armenian.

Phrync, 4th cent. B.C. Boeotian courtesan, famous for her beauty; said to have been painted by Apelles, and copied in Praxiteles' Cnidian Venus.

Phrynlchus, 5th cent. B.C. Attic tragic poet.

Phrynlchus, Arabius, 2d cent. Greek rhetorician and grammarian.

Phrynidea. See Pedipalpi.

Phthalelns. Compounds formed by heating phenols with phthalic anhydride. See Fluorescein. The simplest member of the class is phenol phthalein.

Phthalic Acids. C„H4:(COOH),. Dicarboxyl derivatives of benzene; known in three forms: the ortho-, called phthalic acid, the meta-, called isophthalic acid, and the para-, called terephthalic acid. The ortho acid is prepared by the action of oxidizing agents on tetrachlornaphthalene. It crystallizes in short prisms or plates; nipt. 184° C; soluble in alcohol and water. On heating it is converted into the anhydride. It is used in the manufacture of phthalic anhydride.

Phthalic Anhydride. C0H«(CO),O. White solid, crystallizing in magnificent prisms, melting at 128° C; prepared by heating orthophthalic acid, and used in preparing the ph trioleins. See Fluorescein and Eosin.

Phthiotts. S.e. Thessaly; birthplace of Achilles.

Phthisis. Any wasting disease, but now usually applied to a disease destroying the tissue of the lung and. for the most part, synonymous with pulmonary consumption. The disease is caused by the ravages of a microphyte, the bacillus of tuberculosis (Koch's bacillus). The disease when well established usually results fatally, and more deaths are attributed to this than to any other single cause. Since its cure is so difficult, especial pains should be taken to prevent its spread. The prevention of the diffusion of the bacilli b3r disinfecting the expectoration of a consumptive and all with which it comes in contact should be carefully attended to. Then there should be personal care of one's health, so as to resist the onslaught of any of the bacilli that may find lodgment in the lungs. See Bacillus Tuberculosis, Koch's Lymph, and Consumption.

Phycochromacese. See Cyanophycele.

Phycocyanln. Characteristic bluish-green pigment contained in the cells of the Cyanophycece. It is soluble in hot water.

Phycoerythrine. Red soluble coloring matter contained in the Floridece (Rhodyphycece) or red Algae.

Phycology. Study of seaweeds; Algology.

Phycomycetes. Sub-class of Fungi, mostly unicellular

or ccenocytic organisms with both sexual and asexual modes of propagation, including many of the moulds.

Phycophaein. Reddish-brown substance obtained from certain of the olive-brown seaweeds.

Phycoxanthln. Yellow substance obtained in alcoholic solution from the olive-green seaweeds and diatoms.

Phylactery. Small square box, inclosing certain texts, worn by the Jews during the hours of morning prayer, on a literal interpretation of Exod. xiii. 9, 16.

Phylactolaemata (lophopoda). Ectoproctous Bryozoa with epistome and a horseshoe-shaped lopliophore. They are all (except Rhabdopleura) fresh-water forms, colonial, and without polymorphism. Cristatella lives as free-moving colonies; Plumatella as fixed colonies.

Phyloe. Attic tribes; at first 4, then 10, finally 12.

Phylarchns, 3d cent. B.C. Historian of Greece 280-220 B.C. Fragments of his work survive.

Phyllidiohranchla. In this group of Opisthobranchs the ctenidia are aborted, and special gills are symmetrically developed from the mantle. See TECTIBRANCHIATA.

Phyllirhoe. Nudibranch belonging to the sub-group Gymnobranchia (q.v.).

Phyllite. Old name given to clay slate or argillaceous schist.

Phyllocladia. Branches which imitate leaves, and in many cases perform the functions of leaves, as with Cacti.

Phyllocyanlll. Greenish-blue substance, obtained from the alcoholic solution of chlorophyll by the action of ether and hydrochloric acid.

Phyllocysts. Cavities in Hydrophyllia.

Phyllodlum. Leaf-like organ developed from the sides of

a petiole, as in many Acacias.

Phyllody. Transformation of floral organs to leaves.

[ocr errors][merged small]

I'lij Home Modified leaves, especially those which perform other than their normal functions.

Phyllophore. Leaf-bearing organs.

Pbyllopoda (branchiopoda). Crustaceans with elongated, segmented body, with numerous, lobed, biramous, leaf-like feet, usually absent on the [Ktsterior segments of the abdomen, except the terminal one. where a caudal fork is often present. The posterior pair of antennas act often as locomotor organs. Some forms have a flat carapace, others have a laterally compressed bivalved shell. Some species produce parthenogenetic summer generations. There are two sub-orders, Branchiopoda and Cladocera.

Phyllopodlum. Petiole of a simple leaf, or petiole and rachis of a compound leaf.

Phyllorhlna. Tribe of Microcheiroptera, characterized by having cutaneous appendages spread on the nose, consisting of a horseshoe-shaped anterior leaf, a medium saddle, and a posterior, vertical, lancetshaped leaf. The Rhinolophidje, MeqaDermid^:. and Phyllostomid.*; (q.v.) are the families included.

[ocr errors]

Phylloslplioneie. Family of minute green AlgcR of the order Siphonacece, occurring within the tissues of other plants.

Phyllostomidae. See Bats.

Phyllotaxy. Study of arrangement of leaves on a stem. Phylloxanthln. See Xanthophyll.

Phylloxera. Genus of plant lice of ab. 20 species (nearly all of e. N. America), which form galls on various plants, principally on the leaves. P. vastatrix of the grape mainly attacks the roots. It was first found in N. America 1854, and was first described by two American entomologists, Asa Fitch and C. V. Riley 1871. It had previously been introduced into France 1863, where the mild winters favored its development; as a result the vines succumbed, being less resistent than those of America, which have become habituated to this parasite. By 1874 the French Government, thoroughly alarmed, offered 300,000 francs for a remedy. The measures that have proven most wingless female from the nrA/»r.if>nl Irive hppn flip of a vine-leaf, showing the practical nave oeen tne enlarged section of one of enforcement of quarthe eggs within It; upper nr,tjn(1 rvirnlfttinna

, eaf, showing the openings amine regulations

of the galls; some of the root* of the vine, against infected dlSshowlng the nodosities caused by the parasites, ^ricts and the introduction of hardy American stock. In 1890, more than 700,000 acres had been replanted with American vines. This pest has also been introduced intoCalifornia. The biology of Phylloxera is most interesting: these lice are so small as to be barely visible, and produce generation after generation of wingless (larval) parthenogenetic females in the root galls. About midsummer the generations become winged and appear above ground, laying eggs of two sizes on the leaves. The large eggs hatch into true females, the small ones into males; both sexes are mouthless, and have only the function of laying fertilized eggs, one from each female. Those laid late in fall rest until spring, but the earlier ones hatch in a short time into prolific, agamic females, that start the cycle over again. If the winters are cold, the larvae hibernate. On some vines the agamic generations are produced in leaf-galls instead of root-galls. Carbon bisulphide, potassium sulphocarbonate and emulsions of petroleum are applied to the vines.

Phylogenetlc Variation. Congenitally acquired im


Life-hlstory of Phylloxera.

[ocr errors]

Portuguese Man-of-war (Physalia pelayica).

provements of the characteristics inherited by an organism from its ancestors, provided such improvements are transmitted to posterity.

Phytogeny (phylogenesis). Race development; or, most broadly, the development of the different species, genera, families, orders, classes, etc., of organisms, according to the evolutionary view, from the simple and original parent species. The species of a genus are more nearly related and have more recent ancestors than species of different genera, and these in turn than species of different families, and so on. Compare Ontogeny.

Phylum. Branch or large division in a system of classification of organisms. Phyogeniaria. Small gonoblastidia of the siphonophore


Physalidse. Sub-order of the Siphonophores, characterized by possessing a very large pneumatocyst (as in the Portuguese man-of-war), with no nectocalyces or hydrophyllia, but with clusters of large and small nutritive polyps, and with gonophores on the ventral side of the sac; also with very long and strong tentacles. The female buds become free medusae.

Physeteridae. See Cato


Physic, Indian. Perennial white-flowered herbs of the genus Porteranthus, natural family Rosacea;, natives of the e. U. S.

Physical Diagnosis.

Method of investigating the nature of a disease by the aid of the senses of the examiners as distinguished from the symptoms detailed by the patient.

Physical Education. This is the system of gymnastics, for the training of muscles of the human body and its consequent healthy development. Throughout all time the strengthening of the body, as a means of defense and attack, was necessary for self-preservation. The early Greeks were skillful with weapons of war and later extended their training, which resulted in the noted Greek Games (q.v,). These were replaced by exhibitions of skill by their slaves. The Romans closely followed the Greeks in their athletics. In the Middle Ages exercise was practiced for its usefulness in war. In the 17th and 18th centuries some efforts were made to encourage gymnastics. Early in the present centuiy Jahn (q.v.) organized gymnastic societies in Germany and invented much of our modern apparatus, and is considered the founder of the modern system, which has extended to IT. S. and other countries. The Swiss system of Clias was introduced in France, Italy and England. Ling invented the Swedish system, which begins with simple movements, gradually extending these to more complex exercises. England developed the sports and games. In U.S. gymnasiums were established by schools and colleges on the German plan. The Harvard system was originated by Dr. Sargent in 1869 and consisted of the use of developing apparatus, regulated for the individual, the movements being the Swedish. Anthropometry (q.v.) is used to guide the exercise. More than 1,000 such gymnasiums have been built in U.S.

Physical Geography. See Geography, Physical.

Physicians, Royal College Of. Founded in London 1518; that of Edinburgh 1617. chartered 1681. Salerno was already termed the Hippocratic City in 9th century. The Arabian medical authors began to be known in Europe through translations ah. 1050.

Physick, Philip Sing, M.D., 1768-1837. Prof. Univ. Pa.

1805-31; "father of American surgery."

Physic Nut. Fruit of Curcas piirgans, found in the E. Indies. It is a small bush with a milky juice; the seeds yield an acrid oil, called Jatroplia-oil, used as a purgative, and in lamps.

Phjrsics. That department of science which treats of matter in its relations to energy. It investigates the phenomena and properties of matter and energy, states the results in terms of some definite measurement, and explains them according to certain principles or laws, regarded as the laws of nature. It was formerly called Natural Philosophy. It includes Mechanics, Gravitation, Cohesion, Elasticity, Acoustics, Optics, Heat, Electricity and Magnetism; the properties o£ masses and molecules.

« PreviousContinue »