• Although the “sceptical chymist” Robert Boyle is generally known as an experimental natural philosopher, he was also the child of a culture of bookish erudition. By quoting diverse classical, medieval, Renaissance and contemporary authors, he gave to his readers the impression that he could avail himself of a very wide range of sources. In some cases, however, his apparent erudition was largely dependant on contemporary doxographical commonplace-books. This article unveils one of these books, Johann Gerhard’s “Decas quaestionum physico-chymicarum de metallis” (1643), which served Boyle as his secret source for past authoritative views on the issue of the growth of metals. We also discuss the way in which he manipulated the information he found in this book in order to increase the credibility of his own discourse.

    1. Introduction
    2. “Observations about the Growth of Metals” (1674)
    3. Gerhard in Boyl’s “Sceptical Chymist”
    4. Johann Gerhard and his chymico-mineralogical work (1643)
    5. How did Boyle know Gerhard’s treatise?
    6. Conclusions
    7. Appendix