Huck blames the return of his no-good pap on his spilling the salt. Huck is deeply superstitious, so when he knocks over the salt he tries to quickly throw some over his left shoulder. Unfortunately, the Widow Douglas catches him and (thinking he was merely playing with the salt) stops him before he can throw it. Therefore, he thinks his bad luck wasn't canceled out. When he sees the imprint of the boot heel in the snow, he knows his pap has come back, and will soon be after his money. Thus, he turns over his money to Judge Thatcher, so his father cannot claim it. When he returns home, his pap is waiting for him, and Huck's bad luck begins.
Towards the beginning of the novel, Huck mentions that one morning he accidentally tipped over the salt-cellar at breakfast. Huck, who is extremely superstitious, attempts to throw the spilled salt over his shoulder but is stopped by Miss Watson. Huck then mentions that even though she put in a good word for him, it wasn't enough to keep off the bad luck. Huck believes that his bad luck from not being able to throw the spilled salt over his shoulder is the reason why his father has returned to take him away from Miss Watson. He then consults Jim and his "magic" hair-ball to learn more about his future. After Huck pays Jim, Jim listens to the hair-ball and tells Huck that his father is not sure what to do yet. Jim says that it is best to rest easy and let pap go his own way. Huck then finds his father's footprints in the snow and goes directly to Judge Thatcher and tells him to take his money.