Bloom's Articles Summaries

"Bertha Mason Rochester as a gothic figure"
 This article explains how Bertha Mason is revealed as a character. It says that she was the daughter of a drunkard and a madwoman. After the her fourth year of marriage to Mr. Rochester, she went mad aswell. As a result, she is locked up on the third floor of Thornfield Mansion. Near the end of the story, it says that Bertha chose to sacrifice her life in order to end her confinement.
"Bertha Mason"
The writer tells how Mr. Rochester was blindly led by his father to marry Bertha Mason, not realizing that she had a family history of relatives going mad. On one account, Bertha attacked her brother, Richard Mason, and later appears to Jane late at night and tears Jane's bridal veil. Althought this happens, Jane is unaware of Bertha Mason's existence until Richard Mason objects to her wedding to Mr. Rochester.
"Jane Eyre and Bertha Rochester"
Bertha Mason is described as an opposite of Jane Eyre and a threat to her happiness.  She is also depicted as a wicked character with a melicious laugh.