Page:EB1911 - Volume 21.djvu/572

 diderivatives of benzene. It forms white crystals, melting at 213° with decomposition into water and phthalic an hydride; the latter forms long white needles, melting at 128° and boiling at 284°. Heated with an excess of lime it gives benzene; calcium benzoate results when calcium phthalate is heated with one molecule of lime to 330°–350°. The acid (and an hydride) are largely used in the colour industry (see ; ).

Phthalyl chloride, C6H4(COCl)2 or C6H4(CCl2) (CO)O, formed by heating the an hydride with phosphorus chloride, is an oil which solidif1es at 0° and boils at 275°. In some reactions it behaves as hav1ng the first formula, in others as having the second. Phthalyl chloride with phosphorus pentachloride gives two phthalylene tetra chlorides, one melting at 88° and the other at 47°. They cannot be changed into one another, and have been given the formulae C6H4(CCl3) (COCl) and C6H4(CCl2)2O. Phthalimide, C6H4(CO)2NH, is formed by heating phthalic an hydride or chloride in ammonia gas or by molecular rearrangement of ortho-cyanbenzoic acid. It forms N-metallic and alkyl salts. Bromine and potash give anthranilic acid, C6H4(NH2)(CO2H). (See .)

Isophlhalic acid is obtained by oxidizing meta-xylene with chromic acid, or by fusing potassium meta-sulphobenzoate, or meta-brombenzoate with potassium formate (terephthalic acid is also formed in the last case). It melts above 300°, and dissolves in 7800 parts of cold water and in 460 of boiling. The barium salt (+6H2O) is very soluble (a distinction between phthalic and terephthalic acids). Uvitic acid, 5-methyl isophthalic acid, is obtained by oxidizing mesitylene or by condensing pyroracemic acid with baryta water.

Terephthalic acid, formed by oxidizing para-diderivatives of benzene, or best by oxidizing caraway oil, a mixture of cymene and cuminol, with chromic acid, as almost insoluble in water, alcohol and ether; it sublimes without melting when heated.

PHTHISIS (Gr.  “wasting”), a term formerly applied (like “Consumption”) to the disease of the lung now known as (q.v.).

PHYLACTERY ( ), a Greek word meaning “guard” (sc. against misfortune), i.e. an amulet. It is applied in the New Testament to the tefillin or “prayer-thongs” worn by orthodox Jews daily at morning-prayer (whether at home or in the synagogue). The title employed in Hebrew, tefillin, seems really to be derived from an Aramaic term meaning “attachments,” “ornaments”; it corresponds to the Biblical Hebrew word rendered “frontlets” (totafôth). The tefillin or phylacteries are worn, one on the left arm (the “hand-tefilla”), and the other on the head (the “head-tefilla”). In each case the leather thongs support a small satchel which is fastened to the arm and the forehead respectively, and contains certain passages of the Law written (in Hebrew) on parchment, viz. Exod. xiii. 1-10 amdand [sic] 11-16, Deut. vi. 4-9 and xi. 13-21. The custom of wearing phylacteries seems to have been derived in the first instance from the Pharisees. By the Sadducees and the generality of the people in the time of Christ it seems not to have been practised Later it became—not without protest—one of the badges of orthodox Judaism. It is significant that the custom is entirely unknown to the Samaritan community.

The phylacteries, together with the “fringe” (tsitsîth) and door-post symbol (mezuza)—which latter consists of a piece of parchment, containing the Hebrew text of Deut. vi. 4-9 and xi. 13-21 enclosed in a glass or metal tube, and fixed upon the right hand post of the door of each dwelling-room in a house—form the three sets of visible signs by which the Israelite is constantly reminded of his duty to God (cf. Num. xv. 39-40; Deut. vi. 9; xi 20). The “fringe” (or “tassels”) was originally attached to the common outer garment—a large square wrap—the loose end of which hung over the left shoulder. This garment with tassels is mentioned in the New Testament (cf. Matt. ix. 20; xiv. 36; xxiii. 5 and parallels). Among modern Jews it has survived in two forms: (1) the fringed praying shawl called talith worn by every male orthodox Jew at the synagogue morning service; and (2) an under-garment, shaped like a chest-protector, one part covering the chest, the other the back, which is worn continuously by male orthodox Jews. It is called Arba Kanfoth (i.e. “Four Corners,” Deut. xxii. 12) or “little Talith,” and is, of course, “fringed.” Both phylactery and mezuza were supposed to keep off hurtful demons (Targ. on Cant. viii. 3).

PHYLARCHUS, a Greek historian, who flourished during the time of Aratus, the strategus of the Achaean League, in the 3rd century His birthplace is variously given as Athens, Naucratis, or Sicyon. He was probably a native of Naucratis, and subsequently migrated to Athens. He was the author of a history in 28 books, covering the period from the expedition of Pyrrhus king of Epirus to Peloponnesus (272) to the death of the Spartan king Cleomenes (220) after his defeat by Antigonus Doson. Polybius (ii. 56-63) charges him with undue partiality for Cleomenes and unfairness towards Aratus; Plutarch (Aratus, 38), who is of the same opinion, did not hesitate to use him freely in his own biographies of Agis and Cleomenes.

PHYLE, a mountain fortress, on a pass leading from Athens to Boeotia and Thebes, and commanding a fine view of the Attic plain. It is situated on the south-west end of Mt Parnes. It is chiefly famous for its occupation by Thrasybulus at the head of the Athenian exiles during the rule of the Thirty Tyrants in 404 After defending himself from attack, with the help of a snowstorm, he succeeded by a venturesome night march in seizing Munychia. Close to Phyle is the cliff called Harma, over which the Pythian lightnings were watched for from Athens.

PHYLLITE (Gr. , a leaf, probably because they yield leaf-like plates, owing to their fissility), in petrology, a group of rocks which are in practically all cases metamorphosed argillaceous sediments, consisting essentially of quartz, chlorite and muscovite, and possessing a well-marked parallel arrangement or schistosity. They form an intermediate term in the series of altered clays or shaly deposits between clay-slates and mica-schists. The clay-slates have a very similar mineral constitution to the phyllites, but are f1ner grained and are distinguished also by a very much better cleavage. In the phyllites also white mica (muscovite or sericite) is more abundant as a rule than in slate, and its crystalline plates are larger; the abundance of mica gives these rocks a glossy sheen on the smooth planes of f1ssility. Many of the best Welsh slates are rich in small scales of white mica, which polarize brightly between crossed nicols. The Cornish slates are still more micaceous and rather coarser grained, so that they might be called mica-slates or even phyllites.

A microscopical section of a typical phyllite shows green chlorite and colourless mica both in irregular plates disposed in parallel order, with a greater or smaller amount of quartz which forms small lenticular grains elongated parallel to the foliation. Grains of iron oxide (magnetite and haematite) and black graphitic dust are very commonly present. Feldspar is absent or scarce, but some phyllites are characterized by the development of small rounded grains of albite, often in considerable numbers. The minute needles of rutile, so often seen in clay-slates, are not often met with in phyllites, but this mineral forms small prisms which may be inter grown with black magnetite; at other times it occurs as networks of sagenite. Other phyllites contain carbonates (usually calcite but sometimes dolomite) in flat or spindle-shaped crystals, which often give evidence of crushing. Very tiny blue needles of tourmaline are by no means rare in phyllites, though readily overlooked. Garnet occurs sometimes, a good example of garnetiferous phyllite being furnished by the whetstones of the Ardennes, in which there are many small isotropic crystals of magnesian garnet. Hornblende, often in branching feathery crystals, is a less frequent accessory. In some phyllites a mineral of the chloritoid group makes its appearance; this may be ottrelite, sismondine or other varieties of chloritoid, and occurs in large sub-hexagonal plates showing complex twinning, and lying across the foliation planes of the rock, so that they seem to have developed after the movements and pressures which gave rise to the foliation had ceased. 