One night in February 1869, Mendeleev experienced that dream that has gone down in history:
At that time, the 63 chemical elements known in the world fell into the corresponding grid and formed a table. They are arranged according to atomic mass and exhibit regular variations as the mass increases.
When Mendeleev woke up, he immediately drew the gourd on the paper and made only one necessary modification. He found that this cyclical change was very similar to the ups and downs of trigonometric functions, so he borrowed the concept of function period and named this table the periodic table .
The Mendeleev statue in the Slovak capital
This is one of the most famous dreams in the history of science, and perhaps not as magnificent as the German chemist Kekuler of his time dreamed of a snake with end to end, thus deciphering the hexagonal ring structure of benzene, but it was even more important.
The United Nations designated 2019 as the "International Year of the Periodic Table of Chemical Elements" and commented: "The periodic table is one of the most remarkable discoveries in the history of science, portraying not only the nature of chemistry, but also the essence of physics and biology." ”
This colored table attached to the back of almost every chemistry textbook naturally has many changes and progress compared to the version that Mendeleev developed from his dream 150 years ago, but the original intention of 150 years ago has been consistent: from the historical data, the young chemistry professor at St. Petersburg University wanted to summarize the laws of the elements, mainly for the purpose of preparing lessons.
1869 Edition Element Periodic Table
However, in Mendeleev's time, at least 4 Western European chemists and 1 American chemist tried the same thing, but they could only sort out twenty or thirty elements. Why did Mendeleev succeed?
Before that cold Russian winter night in February 1869, what foreshadowings had been laid in life, and finally appeared through the power of Morpheus, giving an explosive echo to the question of obsession?
(1) Lost in childhood, the door mother moved three times
In 1834, also on a cold February, Mendeleev was born into an Orthodox family in Tobolsk, Siberia. It was once the second city established by the Russian nation east of the Ural Mountains, the capital of Siberia, but by Mendeleev's time, Tobolsk was in decline and would eventually be completely silenced by missing the Great Trans-Siberian Railway.
Mendeleev's father, Ivan, worked in secondary education, and his mother, Maria, came from a prominent local merchant family. Maria's grandfather founded the first glass factory and printing plant in Siberia, which may be a bit of Mendeleev's "chemical gene".
The couple had a total of 17 children, the youngest of whom Mendeleev was. After he was born, his family became increasingly poor, his father failed cataract surgery, blindness and then unemployment, and his mother had to regain his ancestral glass business, which did not go well.
At the age of 13, Mendeleev's father died and his mother's glass factory was burned to the ground.
Portrait of Mary
However, his early childhood failure did not affect his studies. Mary encouraged him to "patiently search for the divine and scientific truth."
The precocious chemists entered school at the age of 6, with good grades in mathematics and science, and mediocre in literature. He graduated from secondary school at the age of 15, earlier than the stipulated number of years, and the teachers had to change to 16 on his certificate of completion.
In fact, in the next 20 years of Mendeleev's life, the talent that transcends the times will be repeatedly bound by the rules. In the many shoals that followed, he never passed so easily.
Soon he suffered his first major setback in Moscow. Maria, who had a son of Jackie Chan, sent Mendeleev thousands of miles to study, but was rejected by Moscow University because of the "school district" regulations. The following year, the Mendeleev family moved to St. Petersburg, then the capital, and was again rejected by St. Petersburg University because of the "school district".
The "mother of the door" moved three times and sent Mendeleev out of Siberia to study for thousands of miles
Eventually, with the help of ivan's former classmate, in the summer of 1850 Mendeleev entered his father's alma mater, the St. Petersburg Normal College. He performed modestly in the entrance exams, but was nevertheless awarded a scholarship on the condition that he had to teach in secondary school after graduation.
Mendeleev's experience of studying was shrouded in the shadow of death. In 1850, Maria died; in 1851, his rich uncle died; in 1852, his sister Lisa died; in 1853, Mendeleev began coughing up blood, and doctors sentenced him to death for tuberculosis.
But Mendeleev recovered and even went back to school to catch the exams. Despite his health, his grades have steadily improved, from being ranked 25th out of 28 students at the time of admission to being at the top of the list by graduation.
He studied a wide range of topics, such as "primary education in China", "rodents in the St. Petersburg area", "the influence of heat on animal distribution", "paleontological plants", "umbra inorganic analysis", and did not see a clear preference.
But it is worth noting that Mendeleev published his first paper on mineral analysis, written in German. The researcher of this study, Vosklesensky, is a well-known figure in the history of Russian science. Vosklesensky was a student of baron von Liebig, a titan of organic chemistry, and later known as the "father of Russian chemistry".
"Father of Russian Chemistry" Vosklesensky (1808–1880)
This was the first major color of chemistry in Mendeleev's life. Mineral analysis is obviously closely related to the weighing of molecules and the type of atoms.
(2) Non-staff teachers, studying in Germany
For health reasons, Mendeleev turned down the opportunity to continue his studies at the Teachers' College after graduation, planning a trip to the milder southern city of Odessa, which has a great library. However, due to some archival errors, he was accidentally sent to the small city of Simferopol to witness the Crimean War up close. It was close to the front line of the beacon fire, and the hospital was overcrowded. The only fortunate thing is that Mendeleev met a famous surgeon there and diagnosed him as not suffering from tuberculosis.
In May 1856, he returned to St. Petersburg several times and wanted to apply to study abroad. In the previous months, he had prepared his master's thesis on isomers while teaching mathematics and the natural sciences. However, the Teachers' College has been closed. In October 1856, he completed his master's defense at st. Petersburg University with an essay "On the Structure of Silicon Compounds".
At this time, Mendeleev was 22 years old.
Mendeleev as a teenager
Due to the scarcity of college staffing at that time, basically "a turnip and a pit", Mendeleev served as a non-staff faculty member of the university in the next two years, and began a long struggle to "regularize".
He teaches seminars on chemical theory, chemical history, and organic chemistry, and directs experimental research for undergraduates. Because of his low and irregular salary, Mendeleev often wrote for the journals of the Ministry of Education and took on personal training jobs. During this time he was briefly engaged, but then met with repentance.
In the spring of 1859, mendeleev, a foreign teacher, finally studied abroad and received a 22-month scholarship. Instead of immediately choosing a place, he spent months traveling through Western Europe. On his way to Paris, he met Besselot, the thermochemist who proposed the "principle of maximum work", Wu Ci, an organic chemist who prepared alkanes, and Dumas, who proposed the method of burning nitrogen; on his way to Munich, he had a good conversation with the "grandmaster" Liebig; and on his way to Heidelberg, he met the namesakers of Bunsen batteries, Allan Mei flasks and Kirchhoff's law.
He stayed in Heidelberg for a simple reason: he had many fellow countrymen. At that time, about 10 percent of Heidelberg's students came from Russia, forming a large diaspora community.
(3) Self-made equipment, found boiling point
In the southern German town on the banks of the Neckar River, Mendeleev finally had a stable circle of friends: Borodin, who composed the Russian poetry opera "Prince Igor", Sechenov, who dissected frogs and proposed brain reflexes, and Zinin, one of the founders of modern Russian chemistry.
Apparently, Mendeleev was not the only great chemist who was forced to study abroad by the strict establishment of Russian universities at that time. While Mendeleev was working "odd jobs" in China, Chinin worked as a tutor for a Swedish immigrant in the arms business. The family's name was Nobel.
Russian organic chemist Chinin (1812–1880)
In Heidelberg, Mendeleev fell under the inventors of the "Bunsen battery" and the "Bunsen lamp". Bunsen lost his right eye to an experimental explosion, but proposed a spectroscopic method known as the "chemist's eye."
Mendeleev was not satisfied with Bunsen's laboratory conditions. He built his own laboratory in his apartment and bought accurate thermometers and other equipment from the masters of chemistry he met. One of the experimental devices, which he designed himself and is now named Mendeleev pyrotechnics, can accurately measure the density of liquids.
He thus discovered the mystery of the transformation of gases and liquids with temperature and pressure, and proposed that all gases could be liquefied as long as they fell to the "absolute boiling point" (now called "critical temperature"). This was the first important discovery made by Mendeleev independently.
September 3, 1860, was a very critical juncture in hindsight. At that time, karlsruhe near Heidelberg hosted the first International Congress of Chemistry, which was attended by 140 famous European chemists, including Kekulé and Bayer. Cannizzaro from Italy called for the use of standards invented by Avogadro to unify the concepts of atomic weight and molecular weight and resolve long-standing differences.
Cannizzaro of Italy called for the unification of chemistry
Mendeleev, 26, observed the speech. He keenly sensed that a new era was coming, and reported on the outcome of the meeting in an article in the Russian Daily.
On the eve of the unification, the Chemical Empire desperately needed a true constitution.
(4) Supporting the family and working part-time in a crazy way
In 1861, Mendeleev's request to extend his study abroad was not approved by the Russian Ministry of Foreign Affairs. When he returned to St. Petersburg, the ancient empire was undergoing a storm of change, and Alexander II decreed the abolition of serfdom.
Serfdom was abolished in Russia in 1861
Although young chemists are also concerned about the student movement, what is even more urgent is the embarrassment of chai rice oil and salt. St. Petersburg University was shut down due to the political situation in the capital, and he lost his position outside the staff.
Mendeleev was hungry all day long, and had to pay credit for mending clothes. He took on everything he could, teaching chemistry, physics, geography, and running back and forth between several high schools.
Mendeleev was once destitute
Naturally, the fee is also a way to make money. Mendeleev soon began a prolific life in which several bodies and books were handed down. It took less than 4 months after his return to China that Mendeleev completed the first "Organic Chemistry" in Russian history. The book is not only a compilation of previous materials, but also adds new knowledge points. For example, he first proposed the limit theory in his book, arguing that the hydrocarbon ratio of methane CH4 is the lowest of all hydrocarbons.
The 500-page manual sold out quickly. Even better, with the support of Chinin and Vosklesensky, it won the Demidov Prize for Writing the following year. These two played Bole and nobleman many times in Mendeleev's life.
Mendeleev with his first wife, Richeva
Mendeleev was finally able to catch his breath, and he paid off his debts with his bonus and became a family. Now, his marriage to his first wife, Liejiwa, was more facilitated by his sister's "marriage urging", and it seems that there is not much affection. Fifteen years later, 43-year-old Mendeleev will meet Popova, a 19-year-old art student, who fell in love at first sight and thought about committing suicide at one point when her second wedding was obstructed by the church.
(5) Graduated with a doctorate and become a full professor
After writing Organic Chemistry, Mendeleev took over the proofreading of the German Encyclopedia of Technology and wrote several chapters on a whim. He gained an astonishing reputation in publishing, having no doctorate, and was hired as a professor at the St. Petersburg Institute of Applied Technology. It is worth mentioning that the principal of the school at that time was the father of the famous composer Tchaikovsky.
As a result of the preparation of the chapter "Alcohol Measurement" in the encyclopedia, Mendeleev was also hired by the Ministry of Finance as an expert of the Alcohol Technical Committee to solicit new methods and new devices for the precise measurement of the concentration of ethanol solutions in order to reform the liquor tax. He obtained extremely pure ethanol with several cubic distillations, studied the changes in solution volume and density with temperature and water-ethanol ratio in detail, and refined precise and complex formulas as industry standards.
In addition to his salary, Mendeleev also had unexpected gains. He has always been interested in the fundamental physicochemical properties of liquids and solutions. In the process of studying alcohol, he can read out clear compound components from precisely drawn images, that is, the molar ratio of ethanol to water molecules.
This later became the title of his doctoral dissertation: "On the Compounds of Alcohol and Water." On January 31, 1865, Mendeleev became Dr. Mendeleev.
Dr. Mendeleev
This very grounded thesis has left some legends in the alcoholic country, such as the "golden ratio" of vodka's 40 alcohol levels studied by Mendeleev.
At the beginning of 1865, another major event occurred, Mendeleev "turned right". After passing the professorial qualification examination, he became a professor of technical chemistry at the University of St. Petersburg and moved into the university apartments in the autumn of the same year. There, he will draw the first version of the periodic table.
In 1867, Voskresensky moved out of St. Petersburg, leaving a vacancy as a professor of pure chemistry to Mendeleev.
At the same time as inheriting the teaching position, Mendeleev also had to inherit the teaching task of his predecessors and old friends: inorganic chemistry. This was relatively unfamiliar to him, and he decided to write a brand new textbook himself.
This epoch-making work, divided into two volumes, was revised 8 times during Mendeleev's lifetime, and revised to the 13th edition after his death, and is still an introductory reading for freshmen majoring in chemistry. The title of the book is Principles of Chemistry.
Title page of the 1897 edition of Principles of Chemistry
However, the chemists who were seriously preparing for the course at that time could not predict the vitality of this textbook, but deeply felt a headache: at that time, there were 63 known chemical elements in the world, and the upper volume of "Principles of Chemistry" only sorted out 8 common elements such as hydrogen H, oxygen O, nitrogen N, carbon C, etc. How to stuff the remaining 55 elements into the next volume?
From the alkali metal lithium Li, sodium Na, potassium K, rubidium Rb to the halogen elements fluorine F, chlorine Cl, bromine Br, iodine J (editor's note: the chemical symbol of iodine was later determined as I) to the alkaline earth metal magnesium Mg, calcium Ca, strontium Sr, barium Ba, the chemical properties of the elements change according to what laws?
What kind of constitution does chemistry revolve around to constitute the material world that humanity sees and uses to produce?
One winter night after writing the first volume of Principles of Chemistry, Mendeleev experienced that dream that has been famous in history.