Give an instance of this.
Do neutrals combine with other substances?
Name the four alkalies found in the ashes of plants.
Alkalies and acids are of opposite properties, and when brought together they unite and neutralize each other, forming compounds which are neither alkaline nor acid in their character. Thus, carbonic acid (a gas,) unites with lime—a burning, caustic substance—and forms marble, which is a hard tasteless stone. Alkalies and acids are characterized by their desire to unite with each other, and the compounds thus formed have many and various properties, so that the characters of the constituents give no indication of the character of the compound. For instance, lime causes the gases of animal manure to escape, while sulphate of lime (a compound of sulphuric acid and lime) produces an opposite effect, and prevents their escape.
The substances coming under the signification of neutrals, are less affected by the laws of combination, still they often combine feebly with other substances, and some of the resultant compounds are of great importance to agriculture.
ALKALIES.
The alkalies which are found in the ashes of plants are four in number; they are potash, soda, lime and magnesia.
POTASH.
How may we obtain potash from ashes?
What are some of its agricultural uses?