Who is the kidnapper in The Call of the Wild?

Manuel is the name of one of the gardener's helpers, who ends up kidnapping Buck from Judge Miller's pleasant estate. As a poor gardener’s helper, Manuel struggles to earn enough wages to fund his gambling addiction. Manuel enjoys playing the Chinese lottery but is not a very good gambler and lost a significant amount of money betting. In order to pay off his debts, Manuel decides to kidnap and sell Buck while Judge Miller is at a meeting of the Raisin Growers’ Association. Manuel takes Buck to a little flag station known as College Park, where he sells Buck to a stranger, who then throws Buck into a baggage car.
The train travels north to Seattle, Washington, where Buck attempts to attack a man in a red shirt wielding a club. Buck is beaten senseless and learns never to antagonize or challenge a man with a club. Buck is then sold to two French Canadians and travels to the Northland, where he relies on his primitive instincts to survive in the harsh conditions.