VOL. LXXXIV.] PHILOSOPHICAL TRANSACTIONS. 44/ 



Exper. 5. It melted with borax and soda with ebullition, but neither a blue 

 nor a green colour was produced when melted with the first. 



Exper. 6. Liquid volatile alkali did not extract any blue colour from the pow- 

 dered substance, nor when added to the solution in acids. 



Exper. 7. The solutions in nitric and muriatic acid were colourless, and a 

 piece of paper dipped into this nitric solution burnt with a red flame, which was 

 first observed by Dr. Ash. 



Exper. 8. Phlogisticated alkali, or prussiate of pot-ash, added to a saturated 

 solution, discovered a very slight quantity of blue precipitate, 



Exper. Q. Oxalic acid, or acid of sugar, added to the diluted solution, disco- 

 vered a very slight precipitate. 



Exper. 10. The remaining liquid of the foregoing experiment was mixed with 

 sulphuric acid, till no more precipitate took place, the remaining filtered liquor 

 was saturated with purified pot-ash, and no earth was separated or discovered. 



Exper. 11. A certain quantity of the powdered substance was dissolved, and 

 saturated with nitric acid, and evaporated ; it then crystallized ; the crystals were 

 permanent in air, did not deliquesce, and exhibited triangular and sexangular 

 plates. 



Exper. 12. When dissolved and saturated with muriatic acid, it exhibited on 

 evaporation long six-sided prismatic crystals, which have the broad alternating 

 with the narrow sides, terminating in obtuse trihedral pyramids; this was ob- 

 served by Dr. Crawford, who also found that the salt formed of the substance 

 with acids dissolved in water, produced 5 times more cold than the salt from the 

 barytes in the same acid; that the salt formed by marine acid and this substance, 

 was much more soluble in warm water than in cold, while the muriat of barytes 

 is nearly as soluble in cold as in warm water; that 1 oz. of distilled water dis- 

 solves 3 times as much of the muriat of Strontionite as the muriat of barytes, 

 which makes a distinction between the basis of this substance and the barytes. 



Exper. 13. Nitric acid added to the solution of that substance in muriatic 

 acid, occasioned a decomposition. 



Exper. 14. A quantity of this substance was dissolved in muriatic acid, the so- 

 lution much diluted with distilled water, and afterwards precipitated by diluted 

 sulphuric acid. The precipitate was dried and decomposed by purified pot-ash, 

 by means of heat. The earth which was thus separated, was perfectly freed from 

 saline parts, afterwards dried and calcined, in order to deprive it of moisture. A 

 quantity of this earth was again dissolved in acid, in order to ascertain the quan- 

 tity of carbonic acid, or fixed air, which it contained, and the real proportion of 

 pure earth contained in a certain quantity. 



I then found by accurate experiments, 1st. That 100 grs. of specific sulphuric 

 acid required 133 grs. of the pure earth for saturation. 2dly. That 100 grs. of 



