I'll be even for the most critical point of the book: It is not a "Lost Diary", a diary. Rather it is the memoir of the author who - were known in an American fantasy magazine back in the years after the "marriage" and written under the title "The Secret of Elena's Tomb" - if I'm not mistaken.
How is that relevant? From a diary one can expect that the author does not intend (usually) that other people know the contents. Thus, the content fails unreflected and unfiltered, without justifications, explosive material so. But memoirs are very well designed for an audience and therefore wrote von Cosel wisely in the book, which the reader should know or wanted to.
After all, wrote von Cosel not only of his life in Florida, but also of his youth, which provide information about the strange visions of his "dream girl" and perhaps awaken the more understanding of why precisely the young Elena chose von Cosel.
For this, he wrote virtually nothing about his actual German wife or his children with her in the book. Find place as I said above all his supernatural experiences and his life in the United States until the moment of his release after the scandal.
If these are already memoirs, so one can imagine that von Cosel rather held back with all sorts of juicy details to life with his loved ones: what he supposedly did to his bride reads very platonic, as if he had just spoken to her, she gifted and their recovery continued to work (but reads naturally just as interesting, particularly because of Cosel said yes, she was communicating with him).
The stories should be enjoyed also due to possible embellishments with caution: As alleged by Cosel in his book that Elena Hoyos lifetime promised his marriage plans and was impressed by them. Neutral sources tell against that Hoyos Such was not going and wanted to be cured as a patient from her tuberculosis mainly. But later as a corpse she could not say "no" yes.
Unfortunately also fill some trivialities the already thin book, mainly descriptions of how to set up his Cosel each new home or how it is lived with a certain new neighbors. Do you know the man who lived with a corpse in a house. At least, I personally would like to know more about the latter (yes, I sick soul).
Supplemented the book with a foreword, epilogue (not written by von Cosel) and imagings at the chapter points will (but nothing that would not gegeistert also through the Internet).
Overall, however, it remains an interesting, quite fascinating, nonetheless quickly durchzulesendes book. Granted, it is (for blog entries and other Internet sources), the first work that I read on this story, but at least it comes directly from Carl von Cosel itself.
So if you specifically interested in it - or generally about necrophilia - can thus the "Lost Diaries" give a chance calmly.