He had learned a good deal of natural history and botany--the habits of plants, insects, and animals. Mark Twain's books bear evidence of this early study. His plants, bugs, and animals never do the wrong things. He was learning a good deal about men, and this was often less pleasant knowledge. Once Little Sam--he was still Little Sam then--saw an old man shot down on Main Street at noon day. He saw them carry him home, lay him on the bed, and spread on his breast an open family Bible, which looked as heavy as an anvil. He thought if he could only drag that great burden away the poor old dying man would not breathe so heavily. He saw a young emigrant stabbed with a bowie-knife by a drunken comrade, and two young men try to kill their uncle, one holding him while the other snapped repeatedly an Allen revolver, which failed to go off. Then there was the drunken rowdy who proposed to raid the "Welshman's" house, one sultry, threatening evening--he saw that, too. With a boon companion, John Briggs, he followed at a safe distance behind. A widow with her one daughter lived there. They stood in the shadow of the dark porch; the man had paused at the gate to revile them. The boys heard the mother's voice warning the intruder that she had a loaded gun and would kill him if he stayed where he was. He replied with a tirade, and she warned him that she would count ten--that if he remained a second longer she would fire. She began slowly and counted up to five, the man laughing and jeering. At six he grew silent, but he did not go. She counted on: seven, eight, nine-- The boys, watching from the dark roadside, felt their hearts stop. There was a long pause, then the final count, followed a second later by a gush of flame. The man dropped, his breast riddled. At the same instant the thunder-storm that had been gathering broke loose. The boys fled wildly, believing that Satan himself had arrived to claim the lost soul. That was a day and locality of violent impulse and sudden action. Happenings such as these were not infrequent in a town like Hannibal. And there were events connected with slavery. Sam once saw a slave struck down and killed with a piece of slag, for a trifling offense. He saw an Abolitionist attacked by a mob that would have lynched him had not a Methodist minister defended him on a plea that he must be crazy. He did not remember in later years that he had ever seen a slave auction, but he added: "I am suspicious that it was because the thing was a commonplace spectacle and not an uncommon or impressive one. I do vividly remember seeing a dozen black men and women, chained together, lying in a group on the pavement, waiting shipment to a Southern slave- market. They had the saddest faces I ever saw."