A paper on the history of chemistry

(School of Chemical Engineering xx)

From BC 1500 to AD 1650, alchemists and alchemists began the earliest chemical experiments in palaces, churches, their own homes and smoky forests in search of immortal elixirs and rich gold. There are many books about alchemy in China, Arabia, Egypt and Greece. During this period, many chemical changes between substances were accumulated, which prepared rich materials for the further development of chemistry. This is a magnificent sight that amazes us in the history of chemistry. Later, alchemy and alchemy experienced ups and downs, which made people see its absurd side more. Chemical methods have been properly used in medicine and metallurgy. During the European Renaissance, some books on chemistry were published and the word "chemistry" was used for the first time. Chemistry in English originated from alchemy, namely alchemy. Chemist still retains two related meanings: chemist and pharmacist. These can be said to be chemical relics born out of alchemy and pharmaceutical industry.

Keywords: phlogiston chemistry; Quantum theory; crystal chemistry

Since the emergence of human beings, chemistry has formed an indissoluble bond with human beings. Drilling wood for fire, cooking food with fire, firing pottery, smelting bronzes and ironware are all applications of chemical technology. It was these applications that greatly promoted the development of social productive forces at that time and became the symbol of human progress. Today, chemistry, as a basic subject, plays an increasingly important role in all aspects of science and technology and social life. From ancient times to the present, with the progress of human society, what periods have the development of chemical history gone through?

The ancient period of process chemistry. At this time, the technology of ceramics, metallurgy, wine-making and dyeing of human beings is mainly inspired by practical experience, and through thousands of years of exploration, chemical knowledge has not yet formed. This is the embryonic period of chemistry.

First, the origin of chemistry

The English word for Chemistry is chemistry, French is Chimie and German is Chemie. They all evolved from an ancient word, namely, Latin chemia, Greek Xηwa(Chamia), Hebrew Chaman or haman, Arabic Chema or Kyle, and Egyptian Chemie. Its earliest source is hard to find. According to the available data, it first appeared in the records of Egypt in the fourth century, so some people think that it can be assumed that it comes from the ancient Egyptian word Chemi, but the meaning of this name is very obscure, with the meaning of chaos, concealment, secret or darkness in Egypt and Egyptian art and religion. These meanings are probably because Egypt is the place where western chemical records were born and where ancient chemistry, especially practical chemistry, is extremely developed. For example, in the 1 1 dynasty, there was a sculpture in Egypt, indicating that workers were making glass. It can be seen that Egypt knew how to make glass at least before 2500 BC. From the mummies unearthed in Egypt, we can see that in 12000 BC, we were skilled in using preservatives and dyeing with cloth and silk. Therefore, the ancients named "chemistry" after Egypt or Egyptian art. As for other meaning, it may be because the ancients thought that chemistry was a magical and secret undertaking with religious overtones.

China's chemical history is certainly not inferior. About 5000- 1 1000 years ago, we were able to make pottery. There were highly exquisite bronzes in the Shang Dynasty more than 3,000 years ago. Papermaking, porcelain and gunpowder were great inventions in the history of chemistry. In 16 and 17 centuries, China was the most advanced country in the world. The word "chemistry" was first used in China in 1856. It first appeared in the book Geophysical Exploration Elements published by British missionary william johnson in 1856.

Second, several development stages of chemistry

The ancient period of process chemistry. At this time, the technology of ceramics, metallurgy, wine-making and dyeing of human beings is mainly inspired by practical experience, and through thousands of years of exploration, chemical knowledge has not yet formed. This is the embryonic period of chemistry.

The period of alchemy and medical chemistry. From BC 1500 to AD 1650, alchemists and alchemists started the earliest chemical experiments in the palace, in the church, in their own homes and in the smoky mountains, in order to seek the immortal elixir and rich gold. There are many books about alchemy in China, Arabia, Egypt and Greece. During this period, many chemical changes between substances were accumulated, which prepared rich materials for the further development of chemistry. This is a magnificent sight that amazes us in the history of chemistry. Later, alchemy and alchemy experienced ups and downs, which made people see its absurd side more. Chemical methods have been properly used in medicine and metallurgy. During the European Renaissance, some books on chemistry were published and the word "chemistry" was used for the first time. .

The phlogiston chemical period. From 1650 to 1775, with the accumulation of metallurgical industry and laboratory experience, people have summed up the perceptual knowledge that combustible materials can burn because they contain phlogiston, and the combustion process is the process in which combustible materials release phlogiston, which turns into ashes.

The period of quantitative chemistry is the period of modern chemistry. 1775 or so, lavoisier expounded the oxidation theory of combustion with quantitative chemical experiments, which initiated the era of quantitative chemistry. During this period, many basic laws of chemistry were established, atomism was put forward, the periodic law of elements was discovered, and the theory of organic structure was developed. All these have laid a solid foundation for the development of modern chemistry.

The period of mutual infiltration of science is the period of modern chemistry. At the beginning of the twentieth century, the development of quantum theory made chemistry and physics have a common language, and solved many unresolved problems in chemistry. On the other hand, the infiltration of chemistry into biology and geology gradually solved the structural problems of protein and enzymes.

This article mainly tells the story of chemical history in the past 200 years. This is a period of rapid development of chemistry, a period of changeable situations and heroes. Let's experience the difficulties and obstacles experienced by chemists in those years, trudge tirelessly in the tortuous course of modern chemical history, and appreciate the infinite scenery when they set aside the fog to establish new theories, discover new elements and propose new methods.

Third, the chemistry discipline grows through exploration.

The development of chemistry can be said to be changing with each passing day, especially its marginal disciplines or its branches, such as biochemistry, physical chemistry, crystal chemistry and so on, which are dizzying. At present, the overheated genetic engineering, cloning technology and yoke electric field theory are even more dazzling. And how many chemists have made immeasurable contributions to the development of chemistry throughout the ages. Do you want to know them? Chemical celebrities will bring you closer to them.

The influence of phlogiston theory. Combustible substances, such as carbon and sulfur, have only a little ash after combustion; After calcination of dense metal, more forging ash is obtained, but it is very loose. All this gives the impression that something was taken away as the flame rose. With the rapid development of metallurgical industry, people have a stronger desire to summarize the essence of combustion phenomenon.

1723, Shtal, a professor of medicine and pharmacology at Harley University, published the textbook Fundamentals of Chemistry. He inherited and developed his teacher becher's explanation of burning phenomenon, and formed a complete and systematic theory, which runs through the whole chemistry. Fundamentals of Chemistry is the representative work of phlogiston theory.

Shtal believes that phlogiston exists in all combustible substances and is released during combustion, giving off light and heat at the same time. Combustion is a decomposition process;

Combustible = = ash+phlogiston

Metal = = forging ash+phlogiston

If metal forging ash and charcoal are mixed and heated, the forging ash will absorb phlogiston in charcoal and become metal again, and at the same time, charcoal will lose phlogiston and become ashes. Charcoal, oil and wax are all phlogiston-rich substances, which burn very violently, leaving only a little ash after burning; Stone, plant ash and gold can't burn because they don't contain phlogiston. Alcohol is a mixture of phlogiston and water. When alcohol burns, it loses phlogiston, leaving only water.

Air is a necessary medium to take away phlogiston. The combination of phlogiston and air fills the space between heaven and earth. Plants absorb phlogiston from the air, and animals get phlogiston from plants. So animals and plants are flammable.

When sulfur and white phosphorus rich in phlogiston are burned, phlogiston escapes and becomes sulfuric acid and phosphoric acid. When sulfuric acid is boiled with turpentine rich in phlogiston, and phosphoric acid (P2O5 at that time) is heated with charcoal in a sealed way, phlogiston will be recovered and sulfur and white phosphorus will be produced. When a metal reacts with an acid, it loses phlogiston and produces hydrogen, which is extremely rich in phlogiston. Metals such as iron and zinc are dissolved in CuSO4 5H2O solution to replace copper, which is the result of phlogiston transferring to copper.

Although phlogiston theory is wrong, it unifies a large number of chemical facts under one concept and explains the chemical reactions in metallurgical process. During the 100 years when phlogiston theory prevailed, chemists did a lot of experiments to explain various phenomena and accumulated rich perceptual materials. In particular, phlogiston theory holds that chemical reaction is a process of transferring one substance to another, and substances are conserved in chemical reaction, which lays the foundation of modern chemical thought. The displacement reaction we are studying now is the process of exchanging components between substances; Redox reaction is a process of electron gain and loss; Substitution reaction in organic chemistry is a process in which an atom or group at a certain structural position in an organic compound is replaced by another atom or group. How similar these thinking methods are to phlogiston theory.

Scheler and Priest discovered the method of making oxygen: Swedish chemist Scheler, a respected chemist, was a pharmacist-chemist. He worked in a pharmacy in Cheping Town for a long time and lived in poverty. During the day, he prepares all kinds of medicines for patients in the pharmacy. As soon as he had time, he entered the laboratory and began to get busy. Once, there was an explosion in the backyard, and the owner and customers were still in shock. Scheler came running shamelessly, excitedly pulling the shopkeeper to see his newly synthesized compound and forgetting everything. The shopkeeper loves and is angry with such a clerk, but he never wants to dismiss him because Scheler is the best pharmacist in this city.

In the evening, Scheler can spend his time freely, and he is more devoted to his own experimental research. He redone all the experiments in the chemistry books that he could see at that time. A lot of hard experiments he did made him synthesize many new compounds, such as oxygen, chlorine, pyrotartaric acid, manganate, permanganate, uric acid, hydrogen sulfide, mercuric chloride, molybdic acid, lactic acid, ether and so on. He studied the properties and compositions of many substances and discovered scheelite. Scheler green, a green pigment that has been used up to now, is copper hydrogen arsenite (CuHAsO3) invented by Scheler. So many research results were unique in the eighteenth century, but Scheler published only a small part of them. It was not until the bicentennial of Scheler's birth in 1942 that all his experimental records, diaries and letters were officially published, totaling eight volumes. Among them, Scheler's correspondence with many chemists at that time attracted attention. There are very valuable ideas and experimental processes in the exchange, which have played a role in mutual exchange and inspiration. Lavoisier, a French chemist, highly praised Scheler, making him more prestigious in France than in Sweden.

In the correspondence between Scheler and Gann, a university teacher, it was found that Gann was inspired to prove that the bone contained phosphorus because Scheler found phosphorus in the ashes. Before that, people only knew that there was phosphorus in urine.

On February 4th, 1775, 33-year-old Scheler was elected as an academician of Swedish Academy. At this time, the owner had died, and Scheler inherited the pharmacy and continued to carry out scientific experiments in his humble laboratory. Due to frequent working all night, coupled with the erosion of cold and harmful gases, Scheler got asthma. He still often tastes all kinds of substances regardless of danger-he wants to master all aspects of material properties. When he tasted hydrocyanic acid, he didn't know it was highly toxic. On May 2 1786, Scheler, who worked hard for the progress of chemistry all his life, died at the age of 44. Scheler found two ways to make oxygen in 1773. The first method is to decompose KNO3, Mg(NO3)2, Ag2CO3, HgCO3 and HgO by heating to release oxygen.

2KNO3==2KNO2+O2↑

2mg(NO3)2 = = 2 MgO+4 NO2 ↑+ O2↑ⅳ

2Ag2CO3==4Ag+2CO2↑+O2↑

2HgCO3==2Hg+2CO2↑+O2↑

2Hg 0 = = 2Hg+O2↑

The second method is to heat pyrolusite (MnO2) with concentrated sulfuric acid to generate oxygen:

2MnO2+2H2SO4 (concentrated) = = 2MNSO4+2H2O+O2 =

Scheler studied the properties of oxygen. He found that combustible substances burned more violently in this gas, and the gas disappeared after combustion, so he called oxygen "internal heat". Scheler is a believer in phlogiston. He believes that combustion is a process in which "fire" in the air combines with phlogiston in combustible materials, and flame is a compound formed by the combination of "fire" and phlogiston. He wrote his findings and opinions into chemistry about air and fire. This paper was delayed for four years and was not published until 1777. British chemist Priest published a paper shortly after 1774 discovered oxygen.

Pastor always believed in phlogiston theory, even in lavoisier's place, he experimented with the oxygen they found, and after overthrowing phlogiston theory, it remained the same. He called oxygen "defluorination gas". He wrote: I put mice in' dephosphorization gas' and found them very comfortable. I was driven by curiosity and did the experiment myself. I don't think readers will be surprised. When I do my own experiment, I suck it from a big bottle full of this gas with a glass straw. At that time, my lungs felt the same as when I inhaled ordinary air; But after inhaling this gas for a long time, my body and mind have always felt very light and comfortable. Who can say that this gas will not become a general product in the future? But now only two mice and I have the right to breathe this gas. Priest spent most of his life as a priest in Leeds, England, and his hobby was chemistry. 1773, he met Franklin, a famous American scientist and politician, and they later became good friends who corresponded frequently. The priest was inspired and encouraged by many good friends. He wrote a lot about chemistry, electricity, natural philosophy and theology.

1774 Father Li traveled to the European continent. In Paris, he and lavoisier exchanged many views on chemistry. Honest priests sympathized with the French Revolution and made several public speeches in England. A group of people in Britain who opposed the French Revolution burned down his house and laboratory. 1794,61year-old Priest moved to the United States and became a chemistry professor at the University of Pennsylvania. The American Chemical Society thinks that he is one of the earliest scholars who study chemistry in the United States. The house where he lived has now been built into a memorial hall, and the priest award named after him has also become the highest honor in American chemistry.

Lavoisier and his balance: the overthrow of phlogiston theory. French chemist lavoisier originally studied law. 1763, at the age of 20, he obtained a bachelor's degree in law and a lawyer's practice certificate. His father is a lawyer and his family is very rich. So lavoisier did not aspire to be a lawyer, but became interested in botany. Collecting specimens in the mountains often made him interested in meteorology. Later, at the suggestion of his teacher, geologist Gertrude, lavoisier studied chemistry with the famous Parisian professor Runje. Lavoisier's first chemical paper was about the composition of gypsum. He synthesized gypsum from sulfuric acid and lime. When he heats plaster, he gives off steam. Lavoisier carefully measured the mass of gypsum losing water vapor at different temperatures with a balance. From then on, his teacher Rouiller began to use the term "crystal water". This success enabled lavoisier to use the balance frequently and summed up the law of conservation of mass. The law of conservation of mass became his belief and the basis of his quantitative experiment, thinking and calculation. For example, he used this idea to express the fermentation process of converting sugar into alcohol as the following equation:

Glucose = = carbonic acid (CO2)+ alcohol

This is the embryonic form of modern chemical equations. Using an equal sign instead of an arrow to represent the process of change shows his conservation thought. In order to further clarify the profound meaning of this expression, lavoisier wrote: "I can imagine listing the substances involved in fermentation and the products after fermentation as an algebraic expression. Then assume that one item in the equation is unknown, and then calculate their values item by item through experiments. In this way, we can check our experiments with calculations, and then verify our calculations with experiments. I often use this method to effectively correct the preliminary results of experiments, so that I can re-experiment in the right way until I succeed. " As early as when lavoisier was born, the versatile Russian scientist lomonosov put forward the law of conservation of mass, which he called "the law of immortality of matter" at that time, which contained more philosophical implications. However, due to the lack of rich experimental basis, especially when Russian science is still very backward, Western Europe does not attach importance to Russian scientific achievements, and the "law of material immortality" has not been widely spread.

/kloc-in the autumn of 0/772, lavoisier once weighed a certain amount of white phosphorus to make it burn. After cooling, it was also called the quality of combustion product P2O5, and it was found that the quality increased! He also burned sulfur and found that the quality of combustion products was greater than sulfur. He thinks it must be some gas absorbed by white phosphorus and sulfur. So he made a more detailed experiment: put white phosphorus on the surface of mercury and tie a bell jar, which left some air. When mercury is heated to 40℃, white phosphorus burns rapidly, and then the mercury level rises. Lavoisier described: "This shows that part of the air is consumed, and the remaining air can neither burn white phosphorus nor extinguish the burning candle;" 1 oz of white phosphorus can obtain about 2.7 ounces of white powder (P2O5 should be 2.3 ounces). The added weight is almost the same as the consumed air weight 1/5 volume. "The phlogiston theory holds that combustion is a decomposition process, and the products of combustion should be lighter than combustible materials. But lavoisier's experimental results are the opposite. He wrote the experimental results into a paper and submitted it to the French Academy of Sciences. Since then, he has done many experiments to prove that phlogiston is wrong. 1773 In February, he wrote in the experiment record book: "The experiment I did fundamentally changed physics and chemistry." He named "new chemistry" "anti-phlogiston chemistry".

1774, lavoisier experimented with baking tin and lead. He put the weighed metal into different sizes of flask, sealed it, weighed the metal and flask, and then fully heated it. After cooling, the mass of the metal and the bottle was weighed again, and no change was found. Open the bottle and air will enter. This time, the quality has increased. Obviously, the increase is the quality of the incoming air (set to a). He opened the bottle again, took out the metal forging ash (there was residual metal in the bottle) and weighed it. He found that the added mass was the same as the air entering the bottle (that is, A). This shows that forging ash is a compound of metal and air.

Lavoisier further thought that it would be more telling if you tried to separate air directly from metal forging ash. He tried to decompose iron forging ash (rust), but the experiment was unsuccessful.

After lavoisier made oxygen: In June this year, Priest visited Paris. At the welcome banquet, he talked about "defluorination gas can be obtained from red precipitate (HgO) and lead (Pb3O4)". For lavoisier, who is helpless, this news is a direct encouragement. 165438+1In June, lavoisier heated the red water and silver ash to produce oxygen. Inspired by Scheler, lavoisier even made a locomotive-sized heating device with a condenser in the center. There are six big wheels under the platform to track the sun at any time. From 65438 to 0775, the experimental center in lavoisier has shifted from decomposing metal forging ash to studying oxygen. He found that the increased mass during combustion was just the decreased oxygen mass. It used to be thought that combustible substances absorbed some air when they burned, but actually absorbed oxygen and combined with it, that is, oxidation. This is the theory of combustion oxidation that overturns the phlogiston theory. At the same time, lavoisier also used animal experiments to study the respiratory function, thinking that "oxygen carbonizes in animals to generate carbon dioxide, and at the same time releases heat. This is exactly the same as burning organic matter in the laboratory. " This answers the question of the source of body temperature. Because the air contains 1/4 oxygen (the data comes from the original text), it should contain other gases, which lavoisier calls "carbon gas". After studying the composition of air, lavoisier concluded: "Not all the air in the atmosphere is breathable; When the metal is baked, the part where the air is combined with the metal is sanitary and most suitable for breathing; What is left is a kind of' carbon gas', which cannot maintain the breathing of animals and cannot support combustion. " He unified burning and breathing, and put an end to the wrong idea that air is a pure substance. 1777, lavoisier explicitly ridiculed and criticized phlogiston: "Chemists can only get vague elements from phlogiston, which is very uncertain, so it can be used to explain various things at will. Sometimes this element has weight, sometimes it has no weight; Sometimes it is the fire of freedom, and sometimes it is combined with earth elements to form a fire; Sometimes it is said that it can pass through the micropores on the wall of the container, and sometimes it is said that it cannot penetrate; Can be used to explain both alkaline and non-alkaline, transparent and opaque, colored and colorless. It is really a chameleon, changing its face all the time. " On September 5th this year, lavoisier submitted an epoch-making Introduction to Combustion to the French Academy of Sciences, which systematically expounded the oxidation theory of combustion and turned phlogiston chemistry upside down. This book was later translated into many languages, gradually eliminating the influence of phlogiston. Since then, chemistry has cut off the connection with ancient alchemy, unveiled the veil of mystery and speculation, and replaced it with scientific experiments and quantitative research. Chemistry has entered the period of quantitative chemistry (that is, modern chemistry). So we say that lavoisier is the founder of modern chemistry. Scheler and Priest discovered oxygen before lavoisier, but because their thinking was not open enough, they only cared about the properties of specific substances and failed to break through the bondage of phlogiston. It's a pity to miss the truth.

Another great contribution of lavoisier to chemistry is to define the four-element theory and three-element theory of ancient Greek philosophers, and dialectically expound the concept of chemical elements based on scientific experiments: "If elements represent the simplest components of matter, then it may be difficult for us to judge what elements are at present; If, on the contrary, we associate elements with the ultimate concept achieved by current chemical analysis, then all substances that we can't decompose in any way now are elements for us. " In the Chemical Summary published by 1789 for four years, lavoisier listed the first Su Zhang Garden and divided the elements into four categories:

Simple materials is ubiquitous in animals, plants and minerals, and can be regarded as material elements: light, heat, oxygen, nitrogen and hydrogen. Simple nonmetallic substances whose oxides are acids: sulfur, phosphorus, carbon, hydrochloric acid, fluoric acid and boric acid. After oxidation, simple metal substances will generate bases that can neutralize acids: antimony, silver, bismuth, cobalt, copper, tin, iron, manganese, mercury, molybdenum, nickel, gold, platinum, lead, tungsten and zinc. Simple materials, salt-forming soil: lime, magnesium soil, barium soil, bauxite, silica soil. Lavoisier's satire and criticism of phlogiston theory and other stale viewpoints are ruthless and intense. This made him offend a large number of contemporary and older generation scientists while creating scientific achievements. In "One Hundred Men Who Influenced World History" and in many books about history, history of science and history of chemistry, the author describes and evaluates lavoisier's personality characteristics in a low-key way, accusing him of not mentioning the enlightenment and help from Scheler and Priest in "Chemical Summary". But we have to see that lavoisier does have extraordinary scientific insight and fearless spirit. Although he was not the first person to discover the method of oxygen production, he analyzed the composition of air through oxygen production and established the oxidation theory of combustion. Therefore, oxygen is different from other gases and is endowed with extraordinary scientific significance. Lavoisier is very diligent. He gets up at six o'clock every day, does experimental research from six to eight, works as a gunpowder director or an academician of the French Academy of Sciences from eight to seven in the afternoon, and devotes himself to his scientific research from seven to ten in the evening. I don't rest on Sunday, and I specialize in experiments all day. When lavoisier got married at the age of 28, his wife was 14 years old. They have no children all their lives, but live a very happy life. She helps lavoisier with his experiments and often stays with him. Many illustrations in lavoisier's works were drawn by his wife. 1789 The French Revolution broke out. Three years later, lavoisier was relieved of his post as director of gunpowder. In June, 1793, 1 1, the National Assembly ordered the arrest of tax collectors of the old dynasty. Lavoisier turned himself in to the prison because he had been a tax official. Mara, far left, had a heated scientific argument with lavoisier and was jealous. He framed lavoisier for having ties with the French enemy and committed treason. 1On May 8th, 794, he was guillotined. In this regard, many people in the scientific community felt very sorry at that time. Lagrange, a famous French Italian mathematician, said sadly, "They can cut off his head in an instant, but his brain may not grow up in a hundred years." At this time, lavoisier was in the prime of life, 5 1 year.

Fourthly, the frontier of chemistry.

China Journal of Sports Medicine 000 124 Genetic engineering, also known as genetic engineering, is a new discipline formed on the basis of the development of molecular biology in 1970s. Genetic engineering is to extract (or synthesize) genetic materials of different organisms at the molecular level, cut, splice and recombine them in vitro, and then introduce recombinant DNA molecules into recipient cells through vectors, so that exogenous DNA can be replicated and expressed in recipient cells. According to people's needs, we can produce different products or directionally create new biological characters, and pass them on to the next generation stably [1]. Genetic engineering technology mainly includes gene isolation, gene purification and gene amplification, and its core is molecular cloning technology. It can help people isolate a single gene from various complex organisms, purify it, and then amplify it in large quantities for research.

In recent 20 years, the rapid development of genetic engineering technology, especially the discovery and application of restriction endonuclease, DNA sequence analysis and DNA recombination technology, not only raised molecular biology to the gene level, but also led other disciplines of biology and medicine to the road of gene research, and made many great achievements in revealing the secrets and life processes. ......