Knots—not slipknots, which we'll hear about later; or bow-knots—but good, hard knots like those Obadiah made, can be cut, although it's better to use your teeth or fingers.
Unfortunately, Dr. Slop has short fingernails and lost his teeth in an obstetrical accident.
No, you don't get any more explanation about that bizarre occurrence. When he tries to use a knife, he slices his thumb open and begins to cuss out Obadiah again.
Mr. Shandy isn't having it. Cursing, he says, has to be proportionate to the situation. There's no good in swearing just a little when something bad happens; you have to swear a lot.
In fact, it's probably a good idea to get all your curses ready ahead of time and then bust them out when the time is right. Mr. Shandy just happens to have a nice violent one handy, if Dr. Slop would like.