Ancient civilizations like the Egyptians, Greeks, and Indians were applying chemistry in various ways as early as 1000 BC without realizing it, such as purifying metals, dyeing cloth, fermentation, and making medicines. Some of the earliest intentional chemical reactions involved processes like fire. The Egyptians were purifying gold as early as 2600 BC. Chemistry later developed into branches including organic chemistry, inorganic chemistry, physical chemistry, and biochemistry. Chemistry now has many applications and roles in industries, forensics, health, teaching, entrepreneurship, and more.