The Optical Papers of Isaac Newton Volume II: The Opticks and Related Papers ca. 1688–1717

items (note 36, p. 222). These letters document exchanges with men of learning on matters of law, religion, prophecy, chemistry, and medicine, as Ranelagh’s opinion was routinely solicited on these matters. The irony, however, is that it is her very prominence that is responsible for her near invisibility. She was so well-known that she was often referred to without using her name. The Hartlib Papers abound with references to ‘that excellent lady our friend’, or ‘that noble lady’ or even just ‘my lady’ – or, in the case of Boyle, ‘a Sister of mine’ (p. 50). This evidentiary problem was exacerbated when Boyle moved inwithRanelagh in1668—because at this point, of course, theyhadnoneed to continue writing to each other, and the documentation of Ranelagh’s scientific activity becomes evenmore sparse (p. 166). The result was that for centuries this person everyone knew, to the extent that there was no need to even identify her, became the person that no one knew. DiMeo’s solution has been to employ the technique of close reading, going through all the correspondence line by line to identify the persons, ideas, and places being referenced. One particularly fruitful example is the way in which the author has unpacked the work being done by Ranelagh’s letter to Hartlib on the alchemical adept Dr. Butler and his version of the philosopher’s stone – the letter adding Ranelagh’s testimony to the description by Jan Baptist vanHelmont, and then beingmarked upbyHartlib for further circulation in his network of scribal publication (p. 118, f. 6). In producing this full-length study, and finding an innovative way to approach this multifaceted but difficult subject, DiMeo has given us a deeply researched, comprehensive, and important book, one which finally solidifies a scholarly focus on the woman who still deserves to be known as the ‘incomparable’ Lady Ranelagh.