AND THEIR COMPOUNDS.

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evaporates ; add six pints of boiling water,and strain through strong linen: pass moreboiling water through the rnass on the filtertili it comes away nearly tasteless. Let theimpurities subside in the united liquors, pouroff the clear fluid, and concentrate to sixpints. Let the impurities again settle ; andto the clear liquor, which is to be poured offand heated to ebullition, add carbonate ofsoda, previously dissolved in boiling water,until the acid is completely neutralized.Set the Solution aside to cool and crystallize.More crystals will be obtained by successive-ly evaporating, adding a little carbonate ofsoda tili the liquid exerts a feeble alkalinereaction on litmus-paper, and then allowingit to cool. Preserve the crystals in well-closed vessels.

SODAE SULPHAS.

Takeofthe Salt which remains afterpreparingpure muriatic acid, two pounds ;Boiling-water, three pints :White marble, in powder, a suffi-ciency;Dissolve the salt in the water, add the mar-ble so long as effervescence takes place, boilthe liquid, and when neutral filter it; washthe insoluble matter with boiling-water, ad-ding the water to the original liquid; concen-trate tili a pellicle begins to form, and thenlet the liquid cool and crystallize.