MRS. B.
That is, certainly, the most probable explanation.
Sulphat of soda, commonly called Glauber’s salt, is another medicinal salt, which is still more bitter than the preceding. We must prepare some of these compounds, that you may observe the phenomena which take place during their formation. We need only pour some sulphuric acid over the soda which I have put into this glass.
CAROLINE.
What an amazing heat is disengaged!—I thought you said that cold was produced by the melting of salts?
MRS. B.
But you must observe that we are now making, not melting a salt. Heat is disengaged during the formation of compound salts, and a faint light is also emitted, which may sometimes be perceived in the dark.
EMILY.
And is this heat and light produced by the union of the opposite electricities of the alkali and the acid?
MRS. B.