The invention of gunpowder had a close relationship with the advanced ancient workmanship of smelting industry. People began to know a lot of chemistry knowledge about the nature of different mineral materials during the process of smelting operation. With the knowledge, ancient necromancers tried to seek the elixir of immortality from certain kinds of ores and fuel. Although they failed to get what they were looking for, they discovered that an explosive mixture could be produced by combining sulfur, charcoal, and saltpeter (potassium nitrate). This mixture finally led to the invention of gunpowder although its exact date of invention still remains unknown.
Many historical materials indicate that gunpowder first appeared before the Tang Dynasty (618-907). From 300 to 650AD several recipes were written about inflammable mixtures. Some historians date the invention of gunpowder at 850AD when a Taoist book warned of three specific elixir formulas as too dangerous to experiment.
The military applications of gunpowder began in the Tang Dynasty. Explosive bombs filled with gunpowder and fired from catapults were used in wars. During the Song and Yuan dynasties (960-1368), the military applications of gunpowder became common and some other weapons like "fire cannon", "rocket", "missile" and "fireball" were introduced.
In the Yuan Dynasty (1279-1368), the method of powder-making was introduced to the Arab world and Europe, bringing a series of revolutions to weapon manufacturing, as well as to stratagem and tactics on the battlefield. From Italy the making of gunpowder soon spread to other European countries, and by the 1350s it had become an effective weapon on the battlefield.
China was the first nation who invented paper. The earliest form of paper first appeared in the Western Han Dynasty (206BC-23AD), but the paper was generally very thick, coarse and uneven in their texture, made from pounded and disintegrated hemp fibers. The paper unearthed in a Han tomb in Gansu Province is by far the earliest existing ancient paper, tracing back to the early Western Han Dynasty.
In the Eastern Han Dynasty (25-220), a court official named Cai Lun made a new kind of paper from bark, hemp, rags, fishnet, wheat stalks and other materials. It was relatively cheap, light, thin, durable and more suitable for brush writing.
The art of paper-making spread east to Korea and Japan at the beginning of the seventh century (the end of the Sui Dynasty and the beginning of the Tang Dynasty). In the eighth century, along with the Silk Road, the Arab countries began to learn how to make paper. It took about 400 years for paper to traverse the Arab world to Europe. In the 14th century many paper mills were established in Italy, from where the workmanship of paper-making spread to the European countries such as Germany. The Italians vigorously produced the material and exported large amounts of it, dominating the European market for many years. In the 16th century, the art of paper-making appeared in Russia and Holland, and it spread to Britain in the 17th century.
Before paper was invented, Qin Shihuang, the first emperor in Chinese history, had to go over 120 kilos of official documents written on bamboo or wooden strips. With the invention of paper, the popularization of knowledge has turned into reality. The invention of paper is an epoch-making event in human history.