NITRATES OF EARTHS. 487 



(d.) Jit 60, dissolves in 1 part of water, and at 212, in some- 

 what more than half its weight. 



(e.) Alcohol does not dissolve it. 



(/.) Deliquescent in moist air ; efflorescent in a dry air. 



(g.) Slightly scintillates on burning charcoal, but with sulphur 

 and charcoal in the proportions of gunpowder, it burns slowly and 

 emits purple sparkles, and a fine green flame. 



(h.) Decomposed by ignition, and pure strontia remains.* 



(i.) A cry 'Stalin a burning candle produces a beautiful blood red 

 flame. 



(j.) The flame of boiling alcohol also acquires a red color from 

 this salt. 



(k.) Decomposed by the sulphuric and muriatic acids, and by baryta, 

 potassa, and soda, 



4. PROPORTIONS. According to Richter, this salt contains, (ex- 

 clusively of water,) acid 5 1. 4 -f 48. 6, base. Stromeyer gives acid 

 50.62 + 49.38, base. These proportions agree with the equivalent 

 weight of the acid 54, and of the base 52. Henry. 



5. USE. To afford pure strontia, and as a test for sulphuric acid ; 

 it is to be used with the same precautions as the nitrate of baryta. 



NITRATE OF LIME. 



1. NATURAL SITUATIONS. In the nitre beds ; in the nitrous earths, 

 and particularly in those of the caverns in the limestone of the wes- 

 tern American States ; in the calcareous cement and plaster of old 

 buildings that have long been inhabited. Its origin, as regards the 

 acid, appears to be from the atmosphere, aided at least in some cases, 

 by nitrogen from animal effluvia. 



2. PREPARATION. 



(a.) By dissolving lime or its carbonate in nitric acid, diluted with 

 5 or 6 parts of water, evaporating to a syrupy consistence, and then 

 allowing it to cool and crystallize. 63 parts of carbonate of lime are 

 decomposed by 90.23 of nitric acid of the density 1.5 and produce 

 103.05 parts of dry nitrate of lime. 



3. PROPERTIES. 



(a.) The crystals are six sided prisms, very acutely terminated ; 

 more frequently it is in fine brilliant needles. 



!b.) Taste acrid and bitter. 

 c.) Sp.gr. 1.6. Suffers the aqueous fusion ; if kept melted for 

 fae or ten minutes and then poured into a heated iron pot, it becomes 

 phosphorescent, and was formerly called Baldwin's phosphorus. f 



* If at the instant of decomposition, a combustible substance be brought into contact 

 with it, a deflagration with a very vivid red flame is produced. Dr. Hope, 

 t From the discoverer, Baldwin, who published an account of this fact in 1675. 



