Men were making use of chemistry long before they knew anything about the science of chemistry. For example, the ancient Egyptians, more than 3,000 years ago, had learned skill in working iron. This metal is found in the earth combined with other materials to make a reddish brown rock-like material. In this form, it is called iron ore. For the Egyptians to separate the metal from the rest of the iron ore required a real use of chemistry. The Egyptians and several other ancient peoples who lived on the shores of the Mediterranean Sea mined silver, gold, lead, tin and copper. They knew how to combine copper and tin to form bronze, a metal that is quite hard, but iron which it is easy to make things. Ancient peoples made spears, swords, helmets, bells, horns, chariots, chairs, pots, pans and a host of other things from bronze. To combine copper and tin in just the right amounts for making bronze was a skill that also required a use of chemistry. The ancient Egyptians could make glass, tile, turpentine, soap and dyes. To make any of these things requires the use of chemistry.
So good were the Egyptians at making them that some of their colored glass and tile have been dug up from the earth where they were buried for thousands of years — and the colors are as bright as when the glass and tile decorated the palaces of Egyptian pharaohs. Egyptian pictures in colored tile show ships with bright-colored stripes dyed in their sails, and nobles, both men and women, wearing beautifully colored clothes. All these facts are still more evidence that the Egyptians knew how to do things that required the use of chemistry. The Romans knew how to make cement. They made such good cement that some of their roads and aqueducts, built of cement two thousand years ago, can still be used today. The hardening of cement is a chemical process. This shows that the Romans, too, knew how to make materials that required the use of chemistry.
An ancient Greek wise man named Empedocles taught that all materials are made of four things called elements: earth, air, water and fire. For two thousand years after Empedocles, certain men tried to make different kinds of materials by combining these four elements in different ways. Fortunately, for the future of chemistry, these men thought of earth as including anything solid, such as ore, metal, salt, glass or wood. Also, they counted any kind of gas as air and any liquid as water.