Page:The chemical history of a candle.djvu/72

70 which I shall use as a test of the presence of water. If I take a little piece of it—it is called potassium, as coming from potash,—if I take a little piece of it, and throw it into that basin, you see how it shews the presence of water by lighting up and floating about, burning with a violent flame. I am now going to take away the candle which has been burning beneath the vessel containing ice and salt, and you see a

drop of water—a condensed product of the candle—hanging from under the surface of the dish. I will shew you that potassium has the