'Edgar's Use Of The Attentive'

This story talks about a man, Edgar, who suffers from a mental illness. He used to stare at objects for many hours.
“This monomania, if I must so term it, consisted in a morbid irritability of those properties of the mind in metaphysical science termed the attentive” tells Edgar (Poe, 1873, para. 6).
There was another character in this story: Edgar’s cousin, Berenice.
She was the exact opposite of Edgar, she was healthy, solar and full of life. But, one day, she got ill of epilepsy and this disease ruined her face, her body and her life bringing her to long periods of catalepsy.
One day she died, she was buried in the garden, but Edgar had a vision about her and her beautiful and white teeth. He was stuck on them for a long time and he went
to snatch them out of her mouth.
As described by Poe (1873), Edgar knew what he had done after one of the servants did notice some objects: it was a spade and with a shriek, he bounded to the table, and grasped the box that lay upon it. And rolled out some instruments of dental surgery, intermingled with thirty-two small, white and ivory-looking substances. (para. 20).