PHONOGRAPHY 



6122 



PHOSPHORUS 



cylinder was then rotated for- 

 wards, and the needle allowed to 

 run over the tin foil, the indenta- 

 tions in which caused the needle 

 to vibrate, and the diaphragm 

 to reproduce the original sounds. 

 In the modern perfected machine, 

 the metal cylinder covered with 

 foil is replaced by a cylinder of 

 wax or its equivalent, in which is 

 cut the sound record. The vibrat- 

 ing diaphragm is commonly of 

 glass, and the machine is driven 

 at a high speed and a uniform 

 rate by an electric motor or 

 springs. See Gramophone ; Talk 

 ing Machine. 



Phonography. System of rapid 

 writing by signs representing 

 sounds. It is better known under 

 the name of shorthand. See Pit- 

 vnan, Isaac ; Shorthand. 



Phonolite (Gr. phone, sound; 

 lithos, stone). In geology, name 

 given to an igneous rock, consisting 

 chiefly of nepheline and sanidine, 

 together with augite, hornblende 

 or biotite. Phonolites have chiefly 

 been formed as lavas, and give out 

 a distinctive clinking sound when 

 struck by a hammer, giving them 

 their alternative name of clink- 

 stones. They decompose easily, 

 owing to weathering into zeolite 

 minerals, and are found in France, 

 Germany, Italy, Cape Verde Is- 

 lands, etc. See Zeolite. 



Phormio (d. c. 428 B.C.). Athe- 

 nian general. He commanded at 

 Potidaea and in Chalcidice, and 

 in 429 B.C. gained two notable 

 naval victories over the Spartans 

 during the Peloponnesian War, in 

 the neighbourhood of Naupactus. 

 In the first battle, Phonnio's 20 

 ships beat the 47 of the Pelopon- 

 nesians ; in the second, his 20 

 beat the Peloponnesians' 77. His 

 death shortly afterwards was a 

 great loss to the Athenians, who 

 erected a statue of him on the 

 Acropolis. 



Phosgene (Gr. phos, light ; root 

 gen, to produce). CO Cl^ Alterna- 

 tive name for carbonyl chloride. 

 A gas discovered by J. Davy in 

 1811, and possessing an unpleasant 

 pungent smell. Used in the manu- 

 facture of aniline dyes and other 

 organic chemicals, it is formed 

 when chloroform decomposes, and 

 by exposing equal volumes of car- 

 bonic oxide and chlorine to the 

 action of sunlight. 



Phosphates. Mineral deposits 

 largely used in fertilisers. The 

 phosphate rocks found in dif- 

 ferent parts of the world consist 

 largely of fossilised animal re- 

 mains or of mineralised guano. 

 Rocks of this type may contain 

 from 40 to 80 p.c. of tribasic phos- 

 phate of lime. The great value of 

 this material is for fertilising pur- 



poses. Phosphate, however, in its 

 raw state, is not soluble in water. 

 It therefore must be chemically 

 treated and turned into super- 

 phosphate before its phosphoric 

 acid becomes available as plant 

 food. It was in 1845 that Henslow 

 first called attention to the de- 

 posit of coprolites below the chalk 

 in Surrey and elsewhere. Since 

 then large deposits of phosphate 

 have been discovered in France, 

 Belgium, South Carolina, Florida, 

 and Tennessee. The use of min- 

 eral phosphates for manure began 

 in the middle cff the 19th century. 

 In 1921 over 5,000,000 tons of raw 

 phosphates were worked up in fer- 

 tilisers. See Basic Slag ; Manures. 



Phosphor Bronze. Alloy of 

 bronze and phosphorus. It is used 

 where great tensile strength or 

 wear-resisting properties are re- 

 quired in parts of machinery, and 

 where iron or steel cannot be used 

 satisfactorily, particularly where 

 the latter would be exposed to the 

 action of salt water. It is em- 

 ployed for bearings of shafts, for 

 pump rods and pump plungers, 

 for valves and cocks, while the pro- 

 pellers for marine launches, motor- 

 boats, destroyers, etc., are often 

 made wholly of it. See Alloy. 



Phosphorescence. Power of 

 emitting light possessed by many 

 animals. It occurs frequently 

 among the Protozoa, jelly-fishes, 

 worms, crustaceans, insects, and 

 fishes, and more rarely in other 

 phyla of the animal kingdom. The 

 familiar phosphorescence of the sea 

 is due to the presence of swarms of 

 the protozoon Noctiluca (q-v.). 

 Another well-known example is 

 seen in the glow-worm, where the 

 light appears to serve the purpose 

 of attracting mates. In the jelly- 

 fishes, phosphorescence accom- 

 panies the power of stinging, and 

 is therefore, probably, of a warning 

 character ; while the angler fish 

 uses it to attract the small species 

 on which it preys. Among animals 

 of the deep sea it serves apparently 

 as an illuminant. 



The means by which the light is 

 produced is not yet fully under- 

 stood, the phosphorescent organs 

 differing greatly in character, 

 while in the Protozoa the entire 

 body protoplasm is luminous. It is 

 probably akin to electrical pheno- 

 mena, but beyond this nothing 

 final can yet be asserted. The 

 luminous qualities often noticed 

 in dead or decomposing fish and 

 crustaceans are due to the presence 

 of phosphorescent bacteria, which 

 belong to the vegetable kingdom. 



A number of substances con- 

 tinue to emit light when placed in 

 darkness after exposure to light. 

 Phosphorus itself does so, but the 



phenomenon is due to oxidation 

 and not to true phosphorescence. 

 Barium and calcium sulphides, all 

 minerals containing aluminium, 

 etc., are phosphorescent. Dewar 

 has shown that phosphorescence 

 increases markedly at very low 

 temperatures. It has been shown 

 that it depends upon the presence 

 of a metal, a soluble flux, and a 

 sulphide of an alkaline earth. 

 Without them phosphorescence 

 does not exist. See Fluorescence. 



Phosphoric Acid. Compound 

 of phosphorus, hydrogen, and oxy- 

 gen, H 3 PO 4 . It is made on a 

 commercial scale by treating bone- 

 ash or mineral phosphate with 

 sulphuric acid in wooden vats and 

 filtering off the phosphoric acid 

 from the precipitated calcium sul- 

 phate. It forms a viscous liquid, 

 and is a tribasic acid forming three 

 series of salts, e.g. NaH 2 PO 4 ; 

 NaJHPO,, ; Na.,P0 4 ; the hydro- 

 gen molecules being gradually re- 

 placed. The salts of the acid are 

 called phosphates. On heating the 

 acid it is converted into pyro- 

 phosphoric acid, H 4 P 2 07, and 

 heating still further results in the 

 formation of metaphosphoric acid 

 HP0 3 , a glassy solid. 



Phosphorous Acid. H 3 P0 3 . Acid 

 formed when phosphorous oxide 

 is added to water, the oxide being 

 produced by the slow oxidation of 

 phosphorus. A solution is ob- 

 tained when sticks of phosphorus 

 are kept exposed to moist air, but 

 the pure acid is made by slowly 

 passing chlorine through phos- 

 phorus melted under water. Its 

 salts are termed phosphites. 



Phosphorus (Gr. phosphoros, 

 light-bringing). P. Chemical ele- 

 ment which derives itsname fromits 

 property of becoming luminous in 

 the dark. It appears to have been 

 discovered in 1669 by Brandt, an 

 alchemist of Hamburg, In 1775 

 Scheele, the Swedish chemist, 

 described a method of making 

 phosphorus from bone-ash. 



Phosphorus does not occur in 

 the free state in nature, but exists 

 combined as phosphate. It is 

 always found in plants, from 

 which animals derive the phos- 

 phate found in bones to the extent 

 of three-fifths of their weight. 

 Large deposits of mineral phos- 

 phates exist, which are now em- 

 ployed in place of bone-ash for the 

 preparation of phosphorus. Pure 

 bone-ash contains the equivalent 

 of over 17 p.c. of phosphorus. 



Phosphorus is chiefly made at 

 Oldbury, near Birmingham, and 

 at Lyons. Concentrated phos- 

 phoric acid is mixed with charcoal, 

 and the dried mixture distilled in 

 retorts. The process occupies 

 about 16 hours. By the Readman, 



