Paracelsus stirred the pool as had not been done for fifteen centuries.
Much more important is the relation of Paracelsus to the new chemical studies, and their relation to practical medicine.

Alchemy, he held, "is to make neither gold nor silver: its use is to make the supreme sciences and to direct them against disease." He recognized three basic substances, sulphur, mercury and salt, which were the necessary ingredients of all bodies organic or inorganic.

They were the basis of the three principles out of which the Archaeus, the spirit of nature, formed all bodies.

He made important discoveries in chemistry; zinc, the various compounds of mercury, calomel, flowers of sulphur, among others, and he was a strong advocate of the use of preparations of iron and antimony.

In practical pharmacy he has perhaps had a greater reputation for the introduction of a tincture of opium--labdanum or laudanum--with which he effected miraculous cures, and the use of which he had probably learned in the East.
Through Paracelsus a great stimulus was given to the study of chemistry and pharmacy, and he is the first of the modern iatro-chemists.