Wikipedia gives me a lot to work with: Isaac Newton's occult studies. The article cites Keynes's essay (which Wilczek emphasized also): "Newton was not the first of the age of reason, he was the last of the magicians."
I'd never heard this apocryphal story about the lab fire and his dog Diamond:
One evening, he left the room for a few minutes, and when he came back he found that his little dog "Diamond" had overturned a candle and set fire to the precious papers, of which nothing was left but a heap of ashes. It was then that he cried, "Oh, Diamond! Diamond! thou little knowest what mischief thou hast done!"
Alongside that apocryphal story is the speculative hypothesis that Newton's nervous breakdown (which did happen) might have been the result of mercury poisoning or some other alchemical mishap, which was also something Wilczek mentioned in his book.
So, reading through the Wikipedia article, I learn that Newton was interested in the Philosopher's Stone and the Elixir of Life, both of which I had heard of, but Diana's Tree is new to me! I will investigate that soon. And the Angelicall Stone too.
And it looks like I will be able to learn lots more here: Chymistry of Isaac Newton. They even have a Unicode Newton Sans font to support the alchemical symbols they need.
I'm also interested in Newton's religious writings, and I can find those at The Newton Project. Such an abundance of excellent online resources!
My Latin should come in handy for the Theatrum Chemicum, which was an important source for Newton too.
I am especially attracted to this idea of the code of nature, like in my old friend the Physiologus. Here's how the Wikipedia article describes Newton's take on the prisca sapientia: "He believed that these men had hidden their knowledge in a complex code of symbolic and mathematical language that, when deciphered, would reveal an unknown knowledge of how nature works."
For Newton's Biblical studies, Wikipedia mentions the influence of Joseph Mede, who is new to me. Definitely worth investigating! This will also be an excuse to learn more about Rosicrucianism.
I need to start bookmarking! Diigo: Alchemy.