Solid sodium combines with solution of magnesium fluoride to form sodium fluoride solution and magnesium metal.

Solid sodium combines with solution of magnesium fluoride to form sodium fluoride solution and magnesium metal is adding hydrochloric acid into form magnesium chloride solution and hydrogen gas. A solution could be copper oxide is combined with solid carbon. This forms copper metal and carbon dioxide gas.

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.