Botulism is a serious, potentially fatal illness caused by a type of poison. The poison – known as botulinum toxin – is produced by a kind of bacteria called Clostridium botulinum. Botulinum toxin is the strongest poison known to science. The toxin can be found in improperly home canned foods and oil infused garlic and herbs. The classic symptoms of botulism include double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, and muscle weakness.