The story of Isaac Newton's alchemical concerns is a relativity recent, but already much explored facet of the father of modern physics. Yes, he was predicting when the world would end using heretical biblical exegesis. Yes, he was trying to spiritualize matter. The "occult" quality of gravity was actually informed by the occult, and his contemporaries were completely justified in criticizing it as such.
Yet what is more interesting to me is how Newton's alchemical project compares to that of Johann Wolfgang von Goethe's. Goethe as a young man, ostensibly a poet and man of letters at this time of his life, went through several years of intensive alchemical study and experimentation. And yet over time he became increasingly critical of the material truth of his project, calling it a "beautiful idea" and instead dedicated a reasonable part of his later intellectual activity to elucidating its spiritual truth.
Thus we have a state in which Newton, the "great" of British science, clung to a literal view of his alchemical work, while Goethe, viewed by some historians of science as a mere dilettante, tried its truths and rejected their materiality, opting instead to focus on the power of the ideas themselves.
The matter becomes only more interesting if you consider the opposition of Goethe's and Newton's optics. But that is a story for another time.
Resources of Interest:
Gray, Ronald D. Goethe the Alchemist: A study of Alchemical Symbolism in Goethe’s Literary and Scientific Works. Connecticut: Martino Publishing, 2002.
Jantz. Harold. “Goethe, Faust, Alchemy, and Jung” in The German Quarterly, Vol. 35,No. 2 (Mar., 1962), pp. 129-141.
Raphael, Alice. Goethe and the Philosophers’ Stone: Symbolic Patterns in ‘The Parable’ and the Second Part of ‘Faust’. London: Routledge and Kegan Paul, 1965.