Note 254 — MINERAL POISONS.
Reading edition
The following is the formula for its preparation. Dissolve ten grains of lunar caustic, in ten times its weight of distilled water; to this add, guttatim, liquid ammonia, until a precipitate is formed; continue cautiously to add the ammonia, repeatedly agitating the mixture until the precipitate is nearly redissolved. The object of allowing a small portion to remain undissolved is, to guard against an excess of ammonia. Wherever the test is used, the liquid to which it is added ought to be quite cold.