Abstract： @@ The first successful demonstrations of clinically useful anesthesia took place a little over 150 years ago. Although both of these public demonstrations were made by dentists, Horace Wells (nitrous oxide) and William Morton (ether), the events revolutionized surgery. Up until that time a surgeon's skill was dependent on how fast he could operate but anesthesia allowed surgeons to take a slower and more careful approach which in turn has allowed surgical innovation and development. Initially anesthesia was given by the most junior person on the surgical team but deaths and an increasing choice of drugs resulted, by the early part of the 20th century, in the development of anesthesia as a separate and distinct medical speciality.