Karl William Scheler

Swedish chemist. 174265438+February 9th, born in Stralsund, Rania,, Apollo (now Germany), 1786 2 1 died in Xue Ping, Sweden on May 20th. 1757 apprenticed as a pharmacist in Gothenburg and began to study and study chemistry. Opened a drugstore in Xueping. In the same year, he was elected to the Royal Academy of Sciences in Stockholm. Scheler discovered more than 30 kinds of organic and inorganic substances. One of the most famous is the discovery of oxygen and chlorine. Before 1773, he studied the burning phenomenon and separated oxygen (he called it "fire air" at that time), and wrote a book about air and fire at the end of 1775, and didn't meet the readers until 1777. In fact, he discovered oxygen one year earlier than J. priestley (1774) in Britain. He also proved that "fire air" exists in air. 1772, Scheler studied nitrogen. He used a mixture of sulfur and iron powder to absorb oxygen in the air to obtain nitrogen. At that time, he called it "air pollution" or "insufficient air". He was the first person to think that nitrogen is one of the components of air. 1774, he made many experiments on pyrolusite, determined that it was a new metal oxide, and named it manganese. It laid a foundation for J.G. Gunn to prepare manganese from this ore in the same year. When Scheler studied pyrolusite, hydrochloric acid was added to this ore powder, and chlorine precipitation was observed, and this gas element was discovered. He discussed this achievement in detail in a paper "On Manganese and Its Properties" sent to the Swedish Institute of Science in 1774. But because he believed in phlogiston theory, he called this gas "phlogiston hydrochloric acid" and didn't think it was an element. Scheler also made many other important discoveries, such as: ① Inorganic acids: phosphoric acid (1774), arsenic acid (1775), molybdic acid (1778) and tungstic acid (178 1). ② Other inorganic compounds: hydrogen fluoride (177 1), hydrogen arsenide (1775), copper arsenite (1778), hydrogen cyanide and cyanide (1782). ③ Organic acids: tartaric acid (1770), oxalic acid (1776), lactic acid and uric acid (1780), citric acid (1784), malic acid (1785), gallic acid and gallic acid. ④ Other organic compounds: casein and concha viola (1780), acetaldehyde and esters (1782), glycerol (1783), etc. The author of On Air and Fire.

Phlogiston theory

The phlogiston theory is the explanation of combustion by chemists a long time ago. They think that fire is a material entity composed of countless tiny and lively particles. The particles of this fire can combine with other elements to form compounds, or they can exist in free form. A large number of free fire particles gather together to form an obvious flame, which is dispersed in the atmosphere, giving people a burning feeling. The fire element composed of such fire particles is "phlogiston".

Phlogiston is filled between heaven and earth and flows in lightning storms. It is contained in the earth, sky, ocean, land, animals, plants, minerals and people's hearts. The atmosphere contains phlogiston, which will cause lightning in the air and make the atmosphere turbulent; Living things are full of vitality when they contain phlogiston; When inanimate matter contains phlogiston, it will burn. Phlogiston not only has various mechanical properties, but also, like the soul, it is a kind of power and a kind of "fire power". Objects lose phlogiston, become ashes, ashes gain phlogiston, and objects will be resurrected.

When a substance is heated, phlogiston cannot decompose automatically. But combustion can only be achieved by adding air to suck out phlogiston; Good air has the property of absorbing phlogiston.

Corrosive agents seize phlogiston in metal, and the metal is corroded; When metals are calcined, they lose their noble light and become dross-when they are endowed with phlogiston, they become arrogant again.

The more phlogiston in an object, the more it burns; Less phlogiston, weak combustion. Good air has the property of absorbing phlogiston, so objects must be in the air to burn; All kinds of entities are composed of basic substances (elements) owned by an object and its unique "gas field", which can be distinguished by fire. When the entity is heated, the "gas field" escapes from the entity.

Because the mass of metals and other substances increases after oxidation, some scientists think that phlogiston, like "halo", repels the center of the earth and has a negative weight (so-called "light weight"), so when metals lose phlogiston, their weight increases instead. Some people say that the loss of phlogiston in metal is like the loss of the soul of the living, so just as the body of the dead is heavier than that of the living, the "dead" ashes are naturally heavier than the living metal. The phlogiston theory proved to be wrong.