What is the theme of "The Birthmark"? Alienation, initiation, problem of guilt or pride?
You could explore the theme of human imperfection or limits as it pertains to Alymer's alchemical over-reaching. Also, you might want to refer to Pygmalion myth and also Frankenstein as they explore a similar theme. A close reading will reveal the conflict between 'nature' and 'spiritual world'-a world travelled by many Romantic authors-British and American. Hope that helps!
A major theme is the presumption of the scientist that he can make human nature/ human form 'better.' Why does Alymer think he can improve on nature? What makes him find his wife's birthmark ugly? YES-- this kind of attitude leads to alienation...and when she dies--it will also lead to guilt! The pride that the intellectual or scientist takes in his (or her) work may lead to a downfall.