Place of publication: [s.l.]
Collation: p. 71-110 : ill. (front. port.) ; 20 cm.
Notes: Drawing of Ralph Waldo Emerson with his signature on front cover. From the library of Dr Moncure Conway. Includes bibliographical references.
Place of publication: London
Collation: 14,  p. ; 18 cm.
Notes: Not dated. Internal evidence suggests 1880. Other works by Cattell advertised inside and on back cover. Part of the NSS pamphlet collection.