In his youth, Thomas Edison built a chemistry lab on a train. When he was 12, Thomas Edison started selling candies and newspapers on the Grand Trunk Railroad, which carried passengers to and from Detroit. Thomas Edison thought his poor hearing helped him concentrate. As a nod to the Morse Code system, he called his two eldest children—Marion Edison and Thomas Edison, Jr.—Dot and Dash, respectively. Truthfully, it was one of many test tubes that were present in the bedroom where Thomas Edison expired on October 18, 1931.