How was Buck's first snow experience? How did this affect Buck?

He sees his first snow, and he does not understand what it is,

At the first step upon the cold surface, Buck's feet sank into a white mushy something very like mud. He sprang back with a snort. More of this white stuff was falling through the air. He shook himself, but more of it fell upon him. He sniffed it curiously, then licked some up on his tongue. It bit like fire, and the next instant was gone. This puzzled him. He tried it again, with the same results. The onlookers laughed uproariously, and he felt ashamed, he knew not why, for it was his first snow.