Claude Berthollet was born into a French family living in the Savoy, a region of France that was then part of Italy. Although the family 's finances had declined, his parents were able to send him to a college in Turin, Italy, where he earned his medical degree in 1768. A few years later, he moved to Paris, France, where he studied chemistry and continued his medical work.

In 1784 Berthollet became director of the Gobelins textile factory. There he began research on the bleaching properties ofchlorine, which had been discovered by Carl Wilhelm Scheele in 1774. Like Scheele, Berthollet originally believed that chlorine was a compound of oxygen rather than an element. Through other experiments he determined the composition of ammonia (NH₃ ) and that the compound potassium chlorate explodes when mixed with carbon. He thought that this compound might replace conventional substances used to make gunpowder. In 1788 Berthollet attempted a...