Salmonella is a kind of bacteria — living things too small to see — that can hide in food and make you badly ill. Chicken, eggs, and food that has sat out too long are the usual trouble; dirty hands and undercooked meat let it through. If it gets into you, you may get fever, stomach pain, and diarrhoea. Papers often say someone has salmonella meaning the food poisoning, though the strict name of the illness is salmonellosis. Cooking food until it is hot enough, keeping raw chicken away from salad, and washing hands are the boring, useful defences. Though actually, the word has nothing to do with the fish salmon. It comes from the scientific name Salmonella, given after an American animal doctor, Daniel Elmer Salmon.