SULPHUR AND NITROGEN COMPOUND Sulphur Compounds.-Phosphorus and sulphur combine energetically to form a series of sulphides, three of which are well defined, viz., P4S7 and P2S5 (see A. Stock, Berichte, 1908 et seq.) ; the first is sometimes used as a substitute for phosphorus in matches, and the last finds application in organic chemistry for replacing oxygen by sulphur. There is also evidence for the existence of P2S3, and possibly Thiophosphates (e.g., and result from the dissolution of in alkalis, whereas by melting it with the sulphides or chlorides of heavy metals, salts analogous to are obtained, which are somewhat unstable in water and still more so towards acids.
Nitrogen Compounds.-Phosphorus pentachloride reacts readily with ammonia to give and thence PC13(NH2)2, chlorophosphamide, which is decomposed by water to PO(NH) or by heat to "phospham," NH:P NI, a white infusible, stable solid ; when PO(NH) (NH2) is heated it gives "phosphoryl nitride," 0 :P N. When ammonia and phosphorus pentasulphide react at a red heat they give a nitride, whereas if the pent oxide is used (in the presence of a trace of water) a series of amides of phosphoric acid result : PO(NH2)2(OH), PO(NH2) and PO(OH) (NH). The interaction of phosphorus penta chloride and ammonium chloride in a sealed tube produces a series of chloronitrides, (PNC12)., where n may be 3, 4, 5, 6 or 7. These give rise to a great variety of complex polymerized compounds by reaction with water.
Therapeutics and Toxicology.-Various preparations of phosphorus are used in the British Pharmacopoeia. The element is essential for the growth of bones in young animals, and hence its compounds are used in rickets. It is also efficient as a nerve
tonic in paralysis agitans, locomotor ataxia, impotence and nervous exhaustion. In some skin diseases, such as psoriasis, chronic eczema and acute indurata, phosphorus is useful. The hypophosphites are recommended in pulmonary affections and are used in tonics, and the glycero-phosphates stimulate meta bolism. Dilute phosphoric acid is used as a gastric stimulant.
Phosphorus is readily accessible in poisonous forms, e.g., in vermin pastes and some matches, and is often taken either in tentionally or accidentally. Symptoms of acute poisoning are usually shown after some delay, with nausea, vomiting, and burn ing sensations in the oesophagus, stomach and abdomen. Emetics and purgatives should be given at once to prevent absorption of the poison. Doses of 3-5 grains of copper sulphate in water at intervals of a few minutes form the harmless copper phosphide. The stomach should be washed out with warm water and then with a 2% solution of potassium permanganate, and this solution should also be given as an enema. Oils, which are effectual in other cases of irritant poisoning, should not be given, for they tend to dissolve phosphorus and retain it in the system; the old French oil of turpentine, however, acts as an antidote in allaying the toxic effects. When yellow phosphorus was used in matches, those engaged in the manufacture used to suffer from a form of necrosis, called "phossy jaw" in England ; the red form now em ployed is, however, non-poisonous. (A. D. M.)