One day a man went into a chemist's shop and said, "Do you have anything to cure a headache?"

The chemist took a bottle from a shelf, held it under the gentleman's nose and took out the cork. The smell was so strong that tears came into the man's eyes and ran down his cheeks.

"What did you do that for?" he said angrily, as soon as he could get back his breath.

"But that medicine has cured your headache, hasn't it?"

"You fool." said the man, "It's my wife that has the headache, not me".