EARTHS. 271 



The composition of the hydrate of strontia according to Dalton, is 

 1 proportion of earth and 12 of water. 



(g.) Strontia imparts to the flame of boiling alcohol, a blood red 

 color ; its effects on the test colors are the same as those of baryta, 

 lime, &ic. 



!h.) No union with fixed alkalies or baryta. 

 i.) Heat readily separates the water from the hydrate, and from 

 the crystals. 



( /.) The compound blowpipe melts the earth itself,* with the char- 

 acteristic red flame. 



(k.) This blowpipe produces a similar flame from every combination 

 of strontia, even from the native minerals. 



(L.) DISTINCTIVE CHARACTERS cannot be confounded with any 

 thing except baryta, but it is lighter than that earth, less caustic, and 

 attracts acids less powerfully ; the strontitic salts being decomposed 

 by baryta, produce different combinations with acids, are less poison- 

 ous, and give a different colored flame. 



5. POLARITY. Like that of baryta, electro-positive, and of course 

 it is attracted to the negative pole in the galvanic series. 



6. COMBINING WEIGHT, 52 composed of strontium one propor- 

 tion, 44, and oxygen one, 8 = 52. 



STRONTIUM. 



1 . Obtained from native carbonate of strontia, by the same pro~ 

 cesses as those which afford barium; discovered by Sir H. Davy, in 

 1808. 



2. PROPERTIES. 



(a.) Similar to those of barium ; has less lustre ; difficult to 

 fuse ; not volatile. 



(b.) Action of air and of water, converts it into strontia; in wa- 

 ter, it produces hydrogen gas. 



(c.) Proportions of the constituents of the protoxide. 



Strontium, 84.54, or 1 equivalent, 44 



Oxygen, - - 15.46, or 1 - 8 



100.00 52 



3. THE DEUTOXIDE OR PEROXIDE of strontium is obtained in pre- 

 cisely the same manner as that of barium. According to Thenard, 

 (II, 314,) it is best obtained by the action of the oxygenized water, 

 or deutoxide of hydrogen upon strontia water; the peroxide of 

 strontium precipitates in brilliant pearly crystals. This oxide, by 



* First effected by Dr. Hare, 18023. See Phil. Trans, of Philad. It is one of 

 the most refractory of natural substances. 



