Though the laundresses spreading sheets of laundry knew how well the sunlight bleached them, producing the whitest of whites, they were unaware of the anti-bacterial effect of the UV of sunlight or how fresh air helped to prevent disease. Deadly and incurable diseases were part of everyday life.The early 19th century laundry procedures, being a major part of the health and hygiene, helped to save lives. Though they did not understand the science, well-trained laundresses had considerable experience in applying various methods. For example, it is said that the ammonia solution created from aged human urine and known as ?渓ant?? neutralized viruses. One of the most common ways to neutralize a virus is to break down the protein and fats (lipids) that hold it together. In the pre-wash, lant neutralized viruses. Here they are shown with the city of Bath in the background