ftl 9 



PHOSPHURETS. 445 



PHOSPHURETS OF THE ALKALIES are scarcely formed, except 

 the transient combination by which phosphuretted hydrogen is pro- 

 duced ; they have but a momentary existence, and pass to the saline 

 condition. 



PHOSPHURET OF LIME. 



1. PREPARATION. 



(a.) A coated glass or earthen tube is partly filled with good lime, 

 in pieces, occupying the middle ; phosphorus is placed at one end, 

 which is stopped with fire lute ; the other end is closed with solid 

 chalk ; lay it across a furnace, and when the lime is red hot, draw 

 the phosphorus into the heat, it sublimes, and the compound is form- 

 ed ; it must be kept close from the air. 



2. PROPERTIES. 



Of an auburn brown color. 



Thrown into water, emits phosphuretted hydrogen, which 

 flashes in the air. 



(c.) Place some of it in a dish of water, and bring over it quickly 

 a jar of common air, which produces a pretty fire work ; we should 

 be on our guard against explosion, which, especially if oxygen gas 

 be used, is very liable to happen. 



(d.) It is said,f that lime and phosphorus stratified in a long vial, 

 buried in sand to the neck, and gradually heated, keeping just be- 

 low redness till the combination is formed, will answer as a substi- 

 tute for the tube experiment, and then the phosphuret may be kept 

 in the same vial.J 



(e.) It is very possible that this substance is, at least in part, a 

 phosphuret of calcium ; but no accurate experiments have been 

 made to determine this point. 



(/.) If phosphorus be sublimed through carbonate of lime, the 

 carbonic acid is decomposed, and charcoal deposited. 



Remark. From half an ounce of good phosphuret of lime, 60 

 cubic inches of phosphuretted hydrogen gas are obtained, by the 

 agency of muriatic acid. 



####*## 



The phosphurets of baryta and strontia may be formed in the 

 same manner, but they possess no properties that are peculiar, ex- 

 cept that the phosphuret of baryta^ is employed for the formation of 

 the hypo-phosphorous acid. 



* If languid, warm water makes it succeed brilliantly, and sulphuric acid, (strong) 

 added to the mixture, has the same effect. Muriatic acid has a similar effect, but 

 not with so much energy. 



t Aikins' Diet. Vol. II, p. 214. 



+ This has not succeeded well with me ; the phosphorus is vaporized before the 

 lime is sufficiently heated. 



See Dr. Pearson's account of the phosphurets in the Phil. Trans. 



