An Old Fart

One evening, a family brings their frail, elderly mother to a nursing home and leaves her, hoping she will be well cared for. The next morning, the nurses bathe her, feed her a tasty breakfast, and set her in a chair at a window overlooking a lovely flower garden.
She seems O.K. but after a while she slowly starts to lean over sideways in her chair. Two attentive nurses immediately rush up to catch her and straighten her up.
Again, she seems O.K. but after a while she starts to tilt to the other side. The nurses rush back and once more bring her back upright. This goes on all morning.
Later, the family arrives to see how the old woman is adjusting to her new home. "So Ma, how is it here? Are they treating you all right?" they ask.
"It's pretty nice," she replies. "Except they won't let you fart."