In this episode of <em>Making Science</em>, Tom Whipple tells the story of physician and alchemist Johannes Baptist van Helmont. In the 17th-century Van Helmont believed he had created the Philosopher's Stone, a substance that could turn base metals into gold. Whilst this might have been a pipe dream his work <em>indirectly</em> paved the way for a monumental scientific discovery - photosynthesis.&nbsp; <hr><p style='color:grey; font-size:0.75em;'> Hosted on Acast. See <a style='color:grey;' target='_blank' rel='noopener noreferrer' href='https://acast.com/privacy'>acast.com/privacy</a> for more information.</p>