Couldn&#x27;t find it in the book itself, but it is referenced here. <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;De_architectura#Materials" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;De_architectura#Materials</a>