Records indicate that around 1781, "when the hospital was imperfectly ventilated, every sixth child died within nine days after birth, of convulsive disease; and that after means of thorough ventilation had been adopted, the mortality of infants, within the same, in five succeeding years, was reduced to one in twenty". This issue was not limited to the Lying-In-Hospital. In that era, ventilation improvement was a general issue in patient care, along with other issues of sanitation and hygiene, and the conditions in which surgeons such as Robert Liston in Britain and elsewhere, had to operate. Florence Nightingale famously worked on the design of safe and healthy hospitals.