For example, for the Gases under pressure hazard class, the hazard categories are Compressed gas, Liquefied gas, Refrigerated liquefied gas and Dissolved gas. These classes relate to the physical state of the gas when packaged and do not describe the degree of hazard.
1 In 1596, a flush toilet was invented and built for Queen Elizabeth I by her Godson, Sir John Harrington. 2  The first patent for the flushing toilet was issued to Alexander Cummings in 1775. 3  During the 1800s, people realized that poor sanitary conditions caused diseases.
First Bathtub in White House Best evidence seems to point to Andrew Jackson as installing the first bathtub with running water between 1829 and 1833. Jackson and his designer spoke with pride that, in their bathroom, you could have a warm, cold, or shower bath.