Most dyes, of both natural and synthetic origin, are organic compounds and dissolve well in the medium they are applied in, normally water from the dye bath. One exception is Prussian blue, which is inorganic in nature. Although mainly used as an artists’ pigment, it can also be used to dye textiles. Prussian blue, discovered by Johann Jacob Diesbach in 1706, was the first modern synthetic inorganic pigment. In the 19th century, it became popular in France for dyeing silk and wool, especially after Napoleon’s Continental Blockade in 1806, which disrupted the access to natural Indigo. After Napoleon’s fall, Prussian blue remained popular, despite the return of natural Indigo. By the 1860s, however, new synthetic organic blue dyes led to a decline in Prussian blue’s use as a dye.