litmus-paper, and then by the nitrate of silver, which forms with it a
dense, white precipitate, the chloride of silver. This is soluble in
ammonia, reappears on neutralizing the ammonia by nitric acid, and is
not redissolved by a large excess of nitric acid, even aided by heat.
Its permanence under an excess of nitric acid distinguishes it from
every other silver salt, but the cyanide; which again is known by
disappearing when boiled with a large excess of the acid.