of red litmus paper, noting the effect. Cleanse the dish, and
treat in the same way a few drops NaOH solution, recording the
result. Do the same with KOH. Acid stains on the clothing, with
the exception of those made by HNO3, maybe removed by NH4OH.
H2SO4, however, rapidly destroys the fiber of the cloth.

Name two characteristics of a base. In the formulae of those
bases, what two common elements? Name the radical. Compare those
symbols with the symbol for water, HOH. Is (OH) positive or
negative? Is the other part of each formula positive or negative?
What are two constituents, then, of a base? Bases are called
hydrates. Write in a vertical line five positive elements. Note
the valence of each, and complete the formula for its base. Affix
the names. Can you see any reason why the three bases above given
are the strongest?

Taking the valences of Cr and Fe, write symbols for two sets of
hydrates, and name them. Try to recognize and name every base
hereafter met with.

A Base is a substance which is composed of a metal, or positive
radical, and OH. It generally turns red litmus blue, and often
has an acrid taste.

An Alkali is a base which is readily soluble in water. The three
principal alkalies are NH4OH, KOH, and NaOH.

Alkali Metals are those which form alkalies. Name three.

An Alkaline Reaction is the turning of red litmus blue.