if one wants to read a serious book of Psychic phenomena then this is not for you.
However, as a tale of human folly it is fascinating stuff.
Schrenck-Notzing had a private fortune that allowed him to indulge in psychical research and he was particularly interested in physical phenomena such as ectoplasm etc. This book details his sittings with two materializing mediums, Eva C [Carrière] and Willi Schneider and the book reproduces many 150+ images from various sittings chronologically over a number of years. Many of these photos are (justly) famous and, of course, all are faked.
Schrenck-Notzing virtually says so in the book: "A strict critic would say that the images look like..." paper cut outs/crude drawings/gloves/bits of cheesecloth or silk etc etc, He even hears the sound of rustling paper and funny coughing noises (regurgitation?) and after taking a photo showing an image that looks like an unfolded picture (you can see the creases) makes a copy of image and (surprise!) he can follow the folds to make a neat little package. He finds some pins and pin holes in the cabinet and still cannot believe its faked as because he could not find out how they were smuggled into the seances he was thus 'forced' to believe that they emanated from the mediums body and were generated by forces unknown.
The reader wants to shout at Schrenck-Notzing, "it IS a bloody bit of muslin/paper cut out etc etc you idiot" (and I did) but the book is now, in the 21st century, not about psychical research but about scientific 'method' and the will to belive and see what you want to. There is also a very odd sexual undercurrent at play, with images of muslin draped over and around nipples and accounts of mediums disrobing and thorough physical examinations.
My edition (the second 1922) has an appendix where Schrenck-Notzing tries to address the issues of fraud and fakery rehashing the 'its just impossible that they could have smuggled it in' argument and printing yet more images of other mediums wearing gloves on their head or regurgitating bits of muslin as if this proved the point that "Look! Others do it too! It must be real."
I must confess I didnt read every account of every sitting and instead found a great image, read the account of relevant seance and Schrenck-Notzing conclusions/rationalizations of it all.
I imagine the P.O.D. versions reproduce the photos in shoddy blurry format. A 'proper' edition has them printed on nice shinier paper and its probably the reason why anyone will buy the book nowadays, although the written accounts contextualise them (One earns how the seances were 'performed') and this make them (Schrenck-Notzing's naivete) and all the more astonishing.
So dont accept a rubbish fake that looks like a book but isnt really, hold out for the real thing.