All I dreamed about Dr. Jekyll was that one man was being...

All I dreamed about Dr. Jekyll was that one man was being pressed into a cabinet, when he swallowed a drug and changed into another being. I awoke and said at once that I had found the missing link for which I had been looking so long, and before I went again to sleep almost every detail of the story, as it stands, was clear to me. Of course, writing it was another thing.