Twain creates pathos when Sally is overjoyed to see Huck and when she is upset that Tom is not back.  Another example is when Huck vows never to upset Sally again.
 
Jim was lonely and wanted Huck to stay.  In additon
 
Tom knew all along that Jim was a free man.  He was unsure of whether to reveal his information.  The information was in between the lines.  Tom could have freed Jim easily with the knowledge of the will, but Tom wanted adventure.
 
Huck believes Jim is "white" on the inside.
 
A coat of arms is a family item passed down through generations.  Tom can not just create one.
 
Tom should be worried about the 
 
Aunt Sally is easily confused.  After a few taking and replacing episodes by Tom and Huck had Aunt Sally totally lost.  Aunt Sally is very trusting of Huck and Tom.  They are her guests and she does not want to disrespect them. 
 
Tom is having Jim do elaborate things that were mentioned in books.  These include keeping wild animals, inscribing a crest on the wall or millstone, and growing a flower in his own tears.  In addition, Huck and Tom take Jim out to help move the millstone.  The plan could have been done quickly, but Tom wants to play the game.
 
Jim and Nat are both very superstitious.  However, Jim is able to tell when something does not sound quite right. Nat is easily persuaded into believing things.  Jim is able to go on his own, but Nat relies on the farm.
 
Huck's plan was simple and quick.  Tom's plan will take more time and has more obstacles that he created.  The boys have a greater