PROOFS OF THE PROPERTIES OF BARYTES.

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try presents, requiring for sulution about 43000 times its weightof water.

Remark. ..Barytes having a strong affinity for sulphuric acid,any other combination of that acid may be made use of insteadof sulphate of soda.

The solution of barytes, or its combinations with nitric, mu-riatic, or acetic acid, are therefore very excellent tests for detect-ing the presence of sulphuric acid. It is consequently a veryimportant re-agent in practical chemistry.

Experiment X.

Barytes is very solulle in water, and shoots on cooling intoregular crystals.

Take barytes, obtained in either of the processes mentionedbefore, put it into a Florence flask, and pour on some distilledwater; boil the solution briskly till a strong pellicle appears,then filter It boiling hot through colourless bibulous paper, freedfrom size, and let the solution cool in a corked phial. Itwill shoot into regular crystals, which if the evaporation has beencarefully conducted, have the form of four-sided prisms of a bril-liant and sattin-like appearance.

Remark. ..These crystals are barytes in a state of absolute pu-rity. They are so soluble as to be taken up again, when heated,merely by their own water of crystallization. When exposed toa strong heat, they swell and foam, and leave a dry white pow-der. At 60° an ounce of water dissolves only 25 grains of them.