New York: The Macmillan Company, 1941. vi, 390p., first issue of the revised version, greyblue cloth boards. Ex libris, library markings on spine, title page, and endsheets; spine is faded also. Only sturdiness recommends this copy.
The text of the first edition, much the same format and typeface, ran to 271 pages. Cameron's preface to the second edition says he's been keeping up with "progress in the field of the oxidative functions, of electrical phenomena and of the effects of drugs upon behavior.."