Public Domain Mark
You can use this work for any purpose without restriction under copyright law. Read more about this licence.
Credit
An essay about the origine & virtues of gems. : Wherein are propos'd and historically illustrated some conjectures about the consistence of the matter of precious stones, and the subjects wherein their chiefest virtues reside. By the Honourable Robert Boyle, Esq; Fellow of the Royal Society. Public Domain Mark. Source: Wellcome Collection.