Chemistry - best defined as the science that deals with the properties and reactions of different kinds of matter.

Chemistry arose from a constellation of interests, the empirical knowledge of metallurgists, brewers, dyers, tanners, calciners,  pharmacists and alchemists.

Alchemy is best defined as: a cosmic art by which parts of the mineral and animal parts - can be liberated from their temporal experience and attain states of perfection, gold in the case of minerals, and for humans, longevity, immortality and finally redemption.

Chinese Alchemy
The first recorded  Chinese alchemist  was Lao Tzu (600 BC) who was influenced by the Taoist religion. 
He perceived the universe in terms of opposites.  The symbol      represented two distinct universal forces.  The male, positive, hot and light principle; the "Yang" versus the female, negative, cool and dark principle; the "Yin".  The eternal struggle between these 2 forces generated the 5 basic earthly elements.

metal earth wood

       The Chinese were less concerned with preparing gold from inferior metals than in preparing 'elixirs' that would bring the human body into a state of perfection and harmony with the universe so that immortality could be achieved.  This meant adjusting the Yin & Yang in the body.  This could be achieved practically by preparing elixirs from substances rich in "Yang" such as red-blooded cinnabar (mercuric sulphide), gold and its salts, or jade.