Modern museum visitors viewing these porcelain vessels in a display case would assume they were serving pieces. While certainly decorative enough for an elegant 18th c. table, they would NEVER be anywhere near the food!
Necessity has always been the mother of invention, and often of design that’s both handsome and useful, too. Visualize the hoops and voluminous skirts of an 18th c. lady, and then consider maneuvering all that yardage each time nature called. This was the solution.
Bourdaloues were chamber pots designed specifically for women wearing such garments. With the assistance of a lady’s maid, they could be slipped beneath skirts and petticoats, employed while standing, and then discretely carried away. Some versions were more practical and fashioned of tin or leather. Many included a lid, perfect for use during a long journey by carriage. Even when skirts shrank in size towards the end of 18th c., the bourdaloue was deemed too practical an item to abandon. They remained in use throughout the Victorian era.
Legend says the name was taken from a celebrated 17th c. French Jesuit priest named Louis Bourdaloue (1632-1704), whose sermons were so infamously long that ladies came to church prepared. Not many historians accept this explanation. Even given that people were more frank about bodily needs in the past than they are now, it’s very doubtful a well-bred French lady would relieve herself in her pew. Though no one now seems to know for certain, it’s likely to be either something garbled in translation, or one more sly English insult aimed at the French.