In To Kill A Mockingbird what are the items found in the tree knothole?

The knothole in the tree is Boo Radley's sole link with the outside world. He fills it with a number of objects, which is his unique way of reaching out to Jem and Scout. When returning home from school one day, Scout sees a piece of tin-foil sticking out of the knothole. Naturally, she's curious, so she opens up the foil and looks inside to find two sticks of gum. When she gets home, she tries one of them, just to make sure it isn't poisoned. But when Jem discovers where Scout found the gum, he makes her spit it out. Boo Radley, though an endless source of fascination for kids in the neighborhood, is still very much a boogie-man figure. Who knows what he might have done to that chewing gum?
Later on, Scout and Jem find another item in the knothole. This time it's a couple of old pennies or "Indian heads" from way back in the early 1900s, buried inside a velvet jewelry box. Boo's gifts get more interesting as the story progresses. Next up is a ball of twine. Jem's still quite wary, but after a few days, when he sees the twine still there, he takes it. Slowly but surely a bond of trust is developing between Boo and the children.
Boo can still be a bit creepy, though. The little figurines of Scout and Jem carved out of soap kind of look like voodoo dolls. Scout certainly thinks so, anyway. But Boo subsequently redeems himself with more conventional gifts such as some more chewing gum (a whole pack this time), a tarnished spelling bee medal from way back when, and a broken old pocket watch.
The kids are truly fascinated by Boo's unusual gifts. They're also deeply grateful and so try to leave him a thank you note in the knothole. Unfortunately they're not able to do this because Nathan Radley, Boo's brother, has filled in the hole with cement. He claims it's because the tree is diseased and needs to be cured. But the kids aren't really convinced; they realize that Nathan's trying to keep Boo isolated from the outside world. He's hacked into his brother's little line of communication with the Finch children, ostensibly to protect him. Yet we're never really sure of his motives. He remains as much of a mystery as Boo, albeit in a different way.