Towns recognized surgery as a livelihood subject to admission and oath to serve the social good. Master surgeons were admitted to practice in 1369 in London in full husting before the mayor and the aldermen and swore to: [1] faithfully serve the people in undertaking their cures, [2] take reasonably from them, [3] faithfully follow their calling, [4] present to the said mayor and aldermen the defaults of others undertaking, so often as should be necessary, [5] to be ready, at all times when they should be warned, to attend the maimed or wounded and others, [6] to give truthful information to the officers of the city as to such maimed, wounded, or others whether they be in peril of death or not, and [7] to faithfully do all other things touching their calling. Some young girls of good families were boarded at nunneries to be taught there. Some upper class widows retired there. Only women were allowed to be present at a birth, at which they spread the knowledge of midwifery. As usual, many women died giving birth. Various ways to prevent pregnancy were tried. It was believed that a baby grew from a seed of the father planted in the woman's body. Infant mortality was especially high in boroughs and burgess family lines usually died out. A three-generation family span was exceptional in the towns, despite family wealth. After the plague, gentlemen no longer had their children learn to speak Norman. The grammar schools taught in English instead of Norman as of 1362. Bishops began to preach in English. English became the official language of Parliament, in 1363, and in the courts, replacing Norman and Latin. The requirements of elementary and higher studies were adjusted in 1393 and began the public school system. William of Wykeham's school, St. Mary College of Winchester in Oxford was the prototype. The curriculum was civil law, canon law, medicine, with astronomical instruments that students made, theology, and the arts. The arts textbooks were still grammar, logic, Donatus, and Aristotle. Many laymen were literate, for instance country gentry, merchants, and craftsmen. Laymen instead of clerics were now appointed to the great offices of state. A will in 1389 in which a wealthy citizen arranges for one son to become an attorney and the other a merchant: