what effect on the character of his new mistress Mrs. auld does douglass ascribe to slavery? what information does Mr. auld unintentionally provide him?

Douglass was elated with his mistress upon their first meeting. She never had slaves before and was dependent upon herself before she was married. She was "in a good degree preserved from the blighting and dehumanizing effects of slavery." She was good, kind, and friendly. Acting sycophantic or ignorant did not work with her; she did not get offended if a slave looked her in the eyes or spoke to her.

Unfortunately, this amiability and kindness was short-lived. She too would become full of rage, menace, capriciousness, and impatience. She was a perfect example of how slavery was not only detrimental for the slave but for the slaveholder as well.

When Douglass first went to live with Mr. and Mrs. Auld, she decided to try and teach him his ABCs. As soon as her husband found out he forbade her to continue the instruction. He explained that if a slave was taught to read, it would spoil him and make him unfit to be a slave. He would become unmanageable and freethinking as well as discontented and morose.