Put a small portion of the compound called mineral chameleon into
several glasses, pour upon each water at different temperatures, and
the contents of each glass will exhibit a different shade of colour. A
very hot solution will be of a beautiful green colour; a cold one, a
deep purple.
Make a colourless solution of sulphate of copper; add to it a little
ammonia, equally colourless, and the mixture will be of an intense blue
colour; add to it a little sulphuric acid, and the blue colour will
disappear; pour in a little solution of caustic ammonia, and the blue
colour will be restored. Thus, may the liquor be thrice changed at
pleasure.