What are 2 examples of alchemy?

Alchemy had a number of specific objectives, which included finding a means of transforming base metals into gold, finding a universal solvent, and creating the Philosopher's Stone. None of these objectives proved to be possible (transmutation was eventually done by means of nuclear physics, but even then, gold can be made only from an isotope of Mercury, not from base metals, and the cost is extremely high, so it is not a source of free wealth as alchemists had hoped).