It was never known with any degree of exactness whether the doctor pulled the valve too far open or whether the engine was working at that moment under extraordinary pressure.

But in the twinkling of an eye Mr.Potts was twisted out of the chair and the movable stand began to execute the most surprising manoeuvres around the room.
It would jerk Mr.Potts high into the air and souse him down in an appalling manner, with one leg among Slugg's gouges and other instruments of torture, and with the other in the spittoon.

Then it would rear him up against the chandelier three or four times, and shy across and drive Potts' head through the oil portrait of Slugg's father over the mantel-piece.

After bumping him against Slugg's ancestor it would swirl Potts around among the crockery on the wash-stand and dance him up and down in an exciting manner over the stove, until finally the molar "gave," and as Potts landed with his foot through the pier-glass and his elbow on a pink poodle worked in a green rug, the machine dashed violently against Dr.Slugg and tried to seize his leg with the forceps.

When they carried Potts home, he discovered that Slugg had pulled the wrong tooth; and Dr.Slugg never sent to collect his bill.