Darquier was born on November 23, 1718 in Toulouse (Rue Darquier 8), France. He worked at his hometown. Using a 2.5 inch achromatic refractor with 42 inch focal length (f/16.8) he observed sunspots and other astronomical phenomena. The observations made between 1748 and 1773 are collected in his book Observations Astronomiques faites Toulouse (Avignon 1777). While searching for the comet of 1779 he discoverd the Ring nebula M 57 in January 1779 (just a few days before Messier) describing it as "a very dull nebula, but perfectly outlined; as large as Jupiter and looks like a fading planet". Friedrich von Hahn found the central star in 1800. William Herschel created the term "Planetary Nebula" in 1785 for those objects looking like a planet's disk - maybe adopting Darquier's description and still impressed by his finding of Uranus in 1781. Darquier observed the new planet in the same year and calculated its orbit. Between 1791 and 1798 he made an extensive star catalogue, later used by Lalande. Darquier died on January 18, 1802 in Toulouse at the age of 83.