What is the book about? Perhaps there is a connection between the topic covered therein, and the feller in the photo?
Based on the signature, if that is what it is, that gent is likely a Brit. Too ornate for a Yank.
For some reason face is vaguely familiar, gut feeling says maybe a scientist or physician whose pic I've may have seen in the past. Google image search with focus on face turned up nothing. Similar search with focus on the signature likewise turned up nothing except useless links to buying vintage signed photos.