The French Revolution that occurred in the late 18th century had a significant impact on not only politics, but French society as a whole. Even after the revolution, there was much hatred against the nobility and especially the luxurious and extravagant lifestyle they lead. Men and women wearing too much clothes and jewellery were punished heavily. There was even a law stating that the weight of your clothes and accessories combined must not exceed 3.5kg. In the early 19th century, the fashion trend changed from the fancy dresses of the past with many decorations to a much more simple, clean and frugal type of dress. A point of interest is that women wearing petticoats (an undergarment worn to puff out skirts) – a key point of the Rococo style – were executed on the guillotine, causing women to quickly throw away their petticoats and try to look as slim as possible. To look thin, women did not even wear underwear. There was a fabric that suited this new fashion trend very well and that was the extremely thin cloth, muslin.
But to follow the fashion of then, it is not enough to simply wear a muslin dress. In early 19th century France, the trend was to douse your dress in water. Why did the women drench themselves in water? The reason being, muslin is a very thin and light cloth that becomes half transparent when wet, while clinging to your body. Women dampened their muslin dress to prove that they were wearing nothing underneath. Also, the ideal, beautiful woman of the time was an intellectual woman who looked fatigued from reading books all night long. Drenching yourself in water adds to this gaunt image, accentuating your fatigue and by extension, your beauty. The woman probably also intended to make the clothing cling to their body to show off their figure (much like the modern day wet t-shirt contests).
The problem was that muslin is an extremely thin material that is unsuitable in the winter or in Northern regions. Considering that women were wearing such a thin dress and even pouring water on themselves, one can imagine how cold they must have been. In fact, France suffered a heavy epidemic of pneumonia in the early 19th century with as much as 60,000 patients turning up with pneumonia every day. A high proportion of these patients were women who liked to wear wet muslin dresses. Thus, the pneumonia was nicknamed muslin disease.