PHOSPHORUS gaseous phosphuretted hydrogen becomes spon- taneously inflammable when raised to the tem- perature of boiling water. When the vapor of trichloride or pentachloride of phosphorus is passed over heated sal-ammoniac a compound is obtained, which was at first supposed to be dinitride of phosphorus, PN 2 ; but accord- ing to Gerhardt it contains hydrogen, having the hypothetical formula HPN 2 , and has been called by him phospham. When it is heated in hydrogen ammonia is formed. With chlorine phosphorus forms a trichloride, PC1 3 , and a pentachloride, P01 5 . The trichloride may be formed by passing dry chlorine gas over dry melted phosphorus in a retort, the vapor which distils over being collected in a receiver sur- rounded by ice. It is a very volatile, fuming liquid, dissolving phosphorus, and being solu- ble in benzole and bisulphide of carbon. It is immediately decomposed by large excess of water into phosphorous and hydrochloric acids. The pentachloride is obtained by exhausting the air from a flask containing dry phosphorus and admitting chlorine, or by adding excess of chlorine to the trichloride. An oxychloride is formed, together with hydrochloric acid, when pentachloride of phosphorus is treated with a quantity of water insufficient to convert it into phosphoric acid. A sulphochloride of similar composition also exists, and an oxybromide and a sulphobromide, also of similar composi- tion, and similarly obtained. There are two iodides, PI 2 and PI 3 . Both are obtained by dissolving phosphorus and iodine together in bisulphide of carbon, and cooling the solution till crystals are deposited. There are six sul- phides of phosphorus : hemisulphide, P4& ; monosulphide, P 2 S ; sesquisulphide, P4S 3 ; tri- sulphide, P 2 S 3 ; pentasulphide, P 2 S B ; and dode- casulphide, P 2 Sia. The mono-, tri-, and penta- sulphides unite with metallic sulphides, form- ing sulphur salts, the copper salts being hypo- sulphosphite of copper, OuSP 2 S, sulphophos- phite of copper, CuSP 2 S 8 , and sulphophos- phate of copper, OuSP 2 S 6 . Selenides are also formed of somewhat analogous composition. Most of the metallic phosphides will be found in the articles on the respective metals. (See also PHOSPHOR BRONZE.) Phosphorus is chief- ly used in the manufacture of lucifer matches, but it is also an important article of the materia medica. In small doses it acts as a powerful general stimulant, in large doses as a violent irritant poison. When not oxidized in the stomach, it is absorbed into the system, proba- bly dissolved in oily matter. Its action, aside from its furnishing through assimilation mate- rial to the nervous system, is directed to the kidneys and genital organs, producing diuresis, and exciting the venereal passion. It has been recommended in impotency, typhoid and typhus fevers, paralysis, locomotor ataxy, and general prostration. The usual form of exhibiting it is in oily solution, sometimes dissolved in oil of turpentine. The solution may be formed into pills, each pill containing one twentieth PHOTIUS 467 of a grain, and one or two of them may be taken two or three times a day. It is also given in the form of diluted phosphoric acid, when it has more the properties of a generai tonic and refrigerant. The dose is 20 drops of the diluted acid, taken in a wine glass of water. Phosphorus is also administered in the form of the hypophosphites, such as lime, soda, and potassa, and of iron, and also combined with iron in the form of pyrophosphate of iron. The alkaline and earthy hypophosphites have obtained considerable celebrity as remedies in tubercular consumption, in combination with a generous and fatty diet ; and the pyrophos- phate of iron in conjunction with calisaya bark, in the form of an elixir, is often used with great benefit as a tonic. PHOTIFS, patriarch of Constantinople, and principal author of the Greek schism, died about 891. The place and time of his birth are unknown. He was related by the marriage of his uncles to the patriarchal and Byzantine imperial houses; and in 857" he was secretary of state to the emperor Michael III. He had made himself necessary both to the emperor and to his minister Bardas. On the deposition of Ignatius, patriarch of Constantinople, on ac- count of his opposition to the court, Photius was installed as his successor (858). The elec- tion was made by the will of Bardas and not by the authorities of the church ; the candidate was a layman, and moreover already a schis- matic, adhering, as it was said, to the party of the Sicilian bishop against the Byzantine pri- mate. Yet in six days he passed through the various grades, and was ordained patriarch. The consent of the neighboring bishops was obtained with difficulty. A council at Con- stantinople of 318 bishops, in 861, confirmed the election, deposing Ignatius. But this decree was soon annulled by another council, called at Rome by Pope Nicholas I., in which Photius was anathematized and ordered to relinquish his claim. Photius called at Constantinople still another council in 867, in which he ex- communicated the pope, and accused the Ro- man church of heresy. On the death of the emperor Michael and the accession of Basil, Photius was banished and Ignatius restored; and in a council held in 869 the acts of the un- lawful council held by Photius were solemnly abrogated and its records burned. After an exile of eight years, Photius was allowed to return to Constantinople ; and in 878, on the death of Ignatius, lie obtained the consent of both emperor and pope to his assumption of the patriarchal place. But he opposed the restoration of the Bulgarians to the jurisdic- tion of the Latin church, and did not recant his own heresies. A new excommunication came from Rome, the sentence of the former Roman council was reaffirmed, and in 886 Photius was finally banished by the emperor Leo to an Ar- menian convent, where he died. Photius has importance in history as the founder of the Greek schism, as a dogmatist, as a philosopher,
