A blaze of fire

　　We often see such scenes in costume dramas: the people in the drama blow a little stick-like thing, and they can fire and cook. Do you think this “stick” is magical? Today, let’s talk about why this thing called the fire zipper burns as soon as it blows.
　　From the appearance, Huozhezi looks like a lipstick. It is a very tight small paper tube made of paper, which is ignited by a fire, then blown out, and then covered with a paper tube cover, leaving a little space. Mars remains on the blown paper tube, which is very easy to burn. When it is needed, a person can make it burn again by blowing it gently.
　　The fire zipper used by ordinary people is made of ordinary paper, and the manufacturing process is relatively simple. However, the material of Huozhuangzi used by Daguanxian is not ordinary, and the production process is more complicated.
　　First, soak the sweet potato in water, take it out after soaking for a certain period of time, crush it, and continue to pound the cherry seeds with cotton and reed; then, dry the pounded mixture, and add flammable things such as sulfur; ， Put all of these into a small bamboo tube, a tall fire fold is done. Compared with those used by ordinary people, such a fire fold is easier to “blow” and more durable.
　　In ancient times, Huozhezi could be regarded as a big black technology. But in fact, in modern times, its principle is very simple, that is, resurgence. The so-called “re-ignition” refers to the phenomenon that something that is already burning is in a state of being half-burned and half-extinguished due to lack of oxygen, and begins to burn immediately when it comes back into contact with oxygen.
　　According to records, the earliest Huozhezi was invented in 577 AD. At that time, during the Wei, Jin, and Northern and Southern Dynasties, there were many wars, and Beiqi suffered enemies. There was a shortage of materials, especially lack of fire, and cooking was a problem. At that time, a group of maidens invented the fire fold, and solved the problem of cooking on the march, allowing the soldiers to have food to eat, and finally won the victory. It can be said that the appearance of Huozhezi has affected the course of history to some extent.
　　The principle of adjusting the concentration of oxygen and then controlling the degree of combustion, like the fire break, is still widely used in honeycomb coal, metallurgy and other fields until today.
　　The fire zipper is small, but it represents the wisdom of the ancient Chinese. It was not until the introduction of modern “foreign fire” from the West that Huozizi was gradually replaced.