What portions of the 1/3 you've read are you be dubious about? I ask because you're the very first person I've encountered that has indicated a need to substantiate that which is already substantiated.
Oh, I am not dubious. I am a believer of Griffin's research. I've only read the beginning 3rd of the book and time restraints and such hasn't led me back to it. At our public library there is a que of 9 people waiting to read it. I was just curious what other books, like Jekyll you've found historically correct and interesting?