Philosophical Letters, 1664 London
Cavendish, Margaret. 1664. Philosophical letters: or, Modest reflections upon some opinions in natural philosophy, maintained by several famous and learned authors of this age, expressed by way of letters / by the thrice noble, illustrious, and excellent princess, the Lady Marchioness of Newcastle. London: [publisher unknown.]
Source library: The Donald F. and Mildred Topp Othmer Library of Chemical History, Chemical Heritage Foundation, Philadelphia, USA.
Record link: http://othmerlib.chemheritage.org/record=b1034755~S3
This image is in the public domain.
For more details on the printing of this work, see Cameron Kroetsch's research, footnote 23: http://www.digitalcavendish.org/wp-content/uploads/2013/08/Kroetsch2013.pdf