The sceptical chymist is a foundational work written by Robert Boyle in 1661 that challenged the traditional views of alchemy and laid the groundwork for modern chemistry. In this text, Boyle questioned the validity of the four-element theory (earth, air, fire, and water) and emphasized the importance of experimentation and empirical evidence in scientific inquiry. This shift marked a significant turning point in the transition from alchemical practices to systematic chemical investigations.