He was visiting the Miners Social Clubs, interviewing ex-miners with the disease. In any research involving the lungs it is essential to know whether the person is exposed to tobacco smoke – his own or other peoples.

“So, John, are you still smoking?”

“I am,” replied John.

“Don’t you know how bad smoking is for the lungs, especially for someone like you with “the dust”?”

“Certainly, doctor, but it’s only smoking that keeps my wife alive!”

“How do you mean?” asked the doctor, clearly very puzzled.

“Well, if I gave up smoking I’d murder the bitch!”