Alchemy, the ancient/medieval precursor of chemistry, comprises many objectives pertaining to the transformation and study of matter. The two biggest are:
1. The transformation of base metals such as lead into gold
2. The development of the elixir of life
The ancient Chinese were perhaps one of the earliest groups of alchemists. Because the Chinese emperor could basically request whatever he wanted, Ge Hong, emperor during the third and fourth centuries CE, asked for an elixir of drinkable gold. I find it quite amusing that a few Chinese emperors died from the elixirs that were supposed to give them immortality (because alchemists weren't particularly good and a lot of elixirs contained mercury).
Ge Hong
Another ancient text from around the same time, ascribed by Democritus, wrote about alchemy in the transformation of metals. Alchemists used techniques such as changing the temperature and heating various metals such as arsenic, mercury, and sulfur.
Alchemy grew become documented in texts by leading scientists and philosophers in wealthy countries, but in the 14th century, the Black Death and Hundred Years' War led to the hunt for witches, so many alchemists began to do their work in code or in secret. By the 18th century, alchemy became restricted to the topic of making gold, and eventually disappeared due to the development of more accurate sciences.