Two Treatises: In the One of which, The Nature of Bodies; In the other, The Nature of Mans Soule, is looked into: In Way of Discovery of the Immortality of Reasonable Soules. by Sir Kenelm Digby. Written in 1644, the last printed edition came out in 1968, and when I wanted to get it out of the university library to use for my dissertation, they had to go and find it in the cellar. I was only the second person ever to check it out, the previous one being in 1973. I've since found a facsimile copy on the Internet Archive, which is on my iLiad. It's not an light read!
