Stewart (P) stopped at Motts' (D) auto repair shop and offered assistance to D in repairing an automobile fuel tank. In an effort to start and move the car without the gas tank attached, P suggested and then poured gasoline into the carburetor. D was to turn the ignition key at a given moment. The car backfired, caused an explosion and resulted in P suffering severe burns to his upper body. The exact sequence of the events is contested. P sued D and asked the judge to instruct the jury that gasoline was a very dangerous substance that required a high degree of care in handling. The judge refused, and the verdict went to D. P appealed.