The manuscript—"On the Preparation of the [Sophick] Mercury for the [Philosophers'] stone by means of the stellate regulus of Mars [i.e. iron] and Luna [i.e. silver] from the Manuscripts of the American Philosopher"—was first published in Latin in 1678 under the title "Experimenta de praeparatione mercurii sophici ad lapidem per regulum martis antimoniatum stellatumque et lunam ex manuscripto philosophici Americani, alias Æyrenæi Philalethes, natu Angli, habitatione cosmopolitæ." This manuscript is a copy in Isaac Newton's hand of an earlier manuscript by George Starkey under his pen name Eirenaeus Philalethes and not a copy of the printed text, so therefore may predate the printed version. Newton's comments in square brackets either expand abbreviations in the other manuscript or correct it.