It opens with this:
How far can the human mind penetrate the mysteries of the great beyond? Who knows? This picture is based upon an extraordinary experiment carried out by Drs. Hughes and Tooney of the University of Los Angeles. There is no doubt as to its authenticity. Testimony of people participating in the experiment sworn to by notary public preclude the possibility of any fraud. This picture is a combination of factual data mixed with fiction.
TCM has an overview.