Keeping mum

Commercial confidentiality has always had an uneasy relation with the Hippocratic oath. In a world of fierce competition, a doctor's duty to share new treatments that have been proved to benefit patients can conflict with financial considerations—and this was so even before the NHS internal market.

None has wrestled with the dilemma for so long—or to such devastating effect—as the Chamberlen family. Over a period spanning roughly 150 years, the Chamberlens handed down the secret of the forceps through four or five generations while protecting their lucrative midwifery business.

Huguenots who …