Paul Bousfield & W.R. Bousfield 
Mind and its Mechanism [PDF ebook] 

First published in 1927, the original blurb reads: "Scientists are beginning to believe there is some immaterial thing which performs certain functions that the material mechanism of the brain is powerless to perform.It is the purpose of this book to explain what that immaterial thing is and how it functions. The Mind and Its Mechanism deals with a theory that may conceivably influence the study of psychology, and will interest not only psychologists, but physiologists, physicists and biologists." Now back in print, this title can be read and enjoyed in its historical context.