STRONTIUM. 489 



The nitrate of barytes is employed as a re-agent, and also in 

 procuring pure barytes. 



The chlorate and hyposulphate of barytes are soluble, the 

 iodate, sulphite, hyposulphite and phosphates of barytes, in- 

 soluble salts. 



SECTION V. 



STRONTIUM. 

 Eg. 547.3, or 43.85; Sr. 



Strontium is prepared in the same way as barium, which it 

 greatly resembles. It is a white metal, denser than oil of 

 vitriol. It derives its name from Strontian, a mining village in 

 Argyleshire. 



Strontian, Strontia, or Strontites ; Sr O; 647.3, or 51.85. 

 The native carbonate of strontian was first distinguished from 

 carbonate of barytes by Dr. Crawford, in 1 790, who conceived the 

 idea that the former mineral might contain a new earth. This 

 conjecture was verified in 1793? by Dr. Hope;* and much 

 about the same time also by Klaproth. The earth, strontian, 

 is to barytes what soda is to potash. It occurs in nature as 

 carbonate and sulphate, but not abundantly. Strontian may 

 be prepared by a strong calcination of the native carbonate in 

 contact with carbon. It is lighter than barytes, and has a taste 

 which is less acrid and caustic, but stronger than that of lime. 

 It is said not to be poisonous. The hydrate crystallizes with 

 9HO, but retains only one equivalent at 212' (Mr. Smith.) 

 This last hydrate enters into fusion at a very high temperature, 

 without losing its combined water. The pure earth, like ba- 

 rytes, is infusible. The crystallized hydrate requires 52 parts 

 of water to dissolve it at 60, but only twice its weight at 212. 



The soluble salts of strontian are prepared from the car- 

 bonate. They are precipitated by sulphuric acid and by soluble 

 sulphates, but not so completely as the salts of barytes, the 

 sulphate of strontian having a small degree of solubility. Hence, 

 when sulphate of soda is added in excess to a salt of strontian, 

 and the precipitate separated by filtration, so much sulphate of 



* Edinburgh Transactions, iv, 14. 



