222 NON-METALS AND THEIR COMBINATIONS. 



not luminous, not soluble in the solvents above mentioned, not com- 

 bustible until it has been heated to about 280 C (536 F.), when it 

 is reconverted into common phosphorus. 



Use of phosphorus. By far the largest quantity of all phos- 

 phorus (both common and red) is used for matches, which are made 

 by dipping wooden splints into some combustible substance, as 

 melted sulphur or paraffin, and then into a paste made by thoroughly 

 mixing phosphorus with glue in which some oxidizing agent (potas- 

 sium nitrate or chlorate) has been dissolved. 



The so-called " safety matches" contain a mixture of antimony trisulphide, 

 red lead, and the chlorate and dichromate of potassium. This mixture will not 

 ignite by simple friction, but does so when drawn across a surface upon which 

 is a mixture of red phosphorus and antimony pentasulphide. 



Pharmaceutical preparations containing phosphorus in the elementary state 

 are phosphorated oil, pills of phosphorus, and spirit of phosphorus. The second 

 is official. 



Phosphorus is also used for making phosphoric acid and other compounds. 



Poisonous properties of phosphorus ; antidotes. Common phosphorus is 

 extremely poisonous, two kinds of phosphorus-poisoning being distinguished. 

 They are the acute form, consequent upon the ingestion of a poisonous dose, 

 and the chronic form affecting the workmen employed in the manufacture of 

 phosphorus or of lucifer matches. 



In cases of poisoning by phosphorus, efforts should be made to eliminate the 

 poison as rapidly as possible by means of stomach-pump, emetics, or cathartics. 

 As antidote a one-tenth per cent, solution of potassium permanganate has been 

 used successfully; it acts by oxidizing the phosphorus, converting it into 

 ortho-phosphoric acid. Oil of turpentine has also been used as an antidote, 

 though its action has not been sufficiently explained. Oil or fatty matter 

 (milk) must not be given, as they act as solvents of the phosphorus, causing its 

 more ready assimilation. 



Detection of phosphorus in cases of poisoning. Use is made of its luminous 

 properties in detecting phosphorus, when in the elementary state. Organic 

 matter (contents of stomach, food, etc.) containing phosphorus will often show 

 this luminosity when agitated in the dark. If this process fails, in consequence 

 of too small a quantity of the poison, a portion of the matter to be examined 

 is rendered fluid by the addition of water, slightly acidulated with sulphuric 

 acid, and placed in a flask, which is connected with a bent glass tube leading 

 to a Liebig's condenser. The apparatus (Fig. 43) is placed in the dark, and 

 the flask is heated. If phosphorus be present, a luminous ring will be seen 

 where the glass tube, leading from the flask, enters the condenser. The heat 

 should be raised gradually to the boiling-point, the liquid kept boiling for 

 some time, and the products of distillation collected in a glass vessel. Phos- 

 phorus volatilizes with the steam, and small globules of it may be found in the 

 collected fluid. If, however, the quantity of phosphorus in the examined 

 matter was very small, it may all have become oxidized during the distillation, 

 and the fluid will then contain phosphorous acid, the tests for which will be 

 stated below. 



