The treatment of patients with myasthenia gravis prior to the year 1934 was ineffective in most cases, with a mortality rate between 80 and 90% within the first two years after the onset of the disease. When Mary Walker1first reported on the use of the anticholinesterase, physostigmine, and later neostigmine, a new era in the pharmacological treatment of this condition began. In 1935 Everts2reported on the oral treatment of patients with myasthenia gravis by the use of tablets of neostigmine (Prostigmin) bromide, each one containing 15 mg. of the substance. In spite of some preliminary skepticism about the wisdom of frequent administration of such tablets to human beings, the successful treatment of many hundreds of cases of this condition was established. During the intervening 20 years since the historical paper of Mary Walker, neostigmine has stood the test of time and experience and is regarded today