Final answer:
John Thornton used the money he won to search for a legendary lost mine in the hope of finding gold. The investment led to perilous adventures and ultimately to a tragic result.
Step-by-step explanation:
The excerpt provided appears to be from a different book and does not pertain to John Thornton or The Call of the Wild. However, answering the original question about John Thornton from The Call of the Wild: After winning the bet, John Thornton paid off his debts and then went on a search for a lost mine, a legend of the north, with potential for great wealth. Thornton believed in the tale of a hidden mine filled with gold. Unfortunately, Thornton's investment did not yield the outcome he had hoped for. He and his companions found themselves in dangerous situations that eventually led to a tragic end.