Rich as he is, he leads a very frugal life. He always wears several outdated gentleman's clothes. He eats very simply, even if he entertains guests at home, he is still a leg of lamb. Cavendish never thought about how to use the money. Once, an old man was introduced by a friend to help him sort out his books. The old man was poor and miserable, and his friends had hoped that Cavendish would give him a bigger reward. But after the work, cavendish said nothing about the remuneration. Afterwards, the friend told cavendish that the old man was extremely poor and asked him for help. Cavendish asked in surprise, "What can I do for him?" The friend said, "Give him some living expenses." Cavendish hurriedly took out a check from his pocket and asked, "Is 20,000 pounds enough?" The friend exclaimed in surprise, "Too much, too much!" But the check has been written. This shows that the concept of money is very weak in cavendish's mind. At that time, the social life of the nobility was extravagant. Cavendish has never set foot in it. He only attends one kind of party, that is, the gathering of scientists of the Royal Society. The purpose is clear: to improve knowledge and understand scientific trends. Witnesses at the time described it like this. When cavendish comes to a party, he always walks into the room quietly with his head down, bent over and his hands behind his back. Then take off your hat, find a place to sit quietly and ignore others. If someone greets him, he will blush and be shy at once. At a party, a member made an experimental demonstration. During the explanation, the member found a ragged and gaunt old man listening carefully. After seeing him, the old man hurried away and hid behind others. After a while, the old man quietly pushed to the front and listened attentively. This strange old man is Cavendish. Many acquaintances know that Cavendish is withdrawn and doesn't like talking to people. Few of his friends can talk to cavendish. Chemist Wollaston is one of them. He summed up an experience: "When talking to cavendish, don't look at him. Look up at the sky as if talking to the air, so that you can hear some of his views." That's it. Cavendish doesn't talk much. He is surprisingly reticent. Among his peers, he may be the one who says the least. The formation of this quirk is related to the environment in which he grew up. When he was two years old, his mother died because she gave birth to her younger brother, and he lost his maternal love. His father is busy with social activities, leaving him in the care of a nanny and rarely contacting the outside world. Until 1 1 years old, he was sent to the aristocratic children's school, where he still had little contact with people, which made him particularly lonely and shy. Because of this eccentric personality, Cavendish lived alone for a long time and immersed himself in his own scientific research world all day. He remodeled some houses in his family. A mansion has been turned into a laboratory, and a residence has been turned into a public library, offering its rich books to everyone. 1733 after his father died, he moved the experimental base to a villa in the country. Remove all the gorgeous decorations in the villa, turn the living room into a laboratory, and the upstairs bedroom into an observatory. Even put up a shelf on the grass in front of the house to climb the tree and observe the stars. As for trampling on those precious flowers and plants, he doesn't care. All these show that he is simply obsessed with scientific research. In social life, he is taciturn and appears very withdrawn. But in scientific research, he is open-minded and has a wide range of interests, which makes him extremely active. He discussed everything from astronomy and meteorology to geology and mining, abstract mathematics and specific metallurgical technology. Especially in the research of chemistry and physics, he has made great achievements and made many important achievements. 1766, Cavendish published his first paper "On the Experiment of Artificial Air". This paper mainly introduces his experimental research on fixed air (that is, carbon dioxide before chemical nomenclature was put forward) and combustible air (that is, hydrogen). As early as 1754, British chemist Blake discovered fixed air, but at that time he only knew that it could be obtained by heating limestone, which existed in the air exhaled by people and was produced by burning charcoal. As for how to collect it, its physical and chemical properties are unknown. Cavendish has done constructive work in these fields. Cavendish inspected the drainage gas collection method for collecting reaction gas. He found that fixed air can be dissolved in water. The volume of fixed air that can be absorbed by water at room temperature is a little larger than that of water itself, and it can absorb more after cooling. If the water is boiled, the fixed air dissolved in the water will escape. The ability of alcohol to absorb fixed air is greater, which is about 2.25 times of its own volume. Some alkali solutions can also dissolve fixed air, so the collection of fixed air can not be carried out by drainage and gas collection, but on the mercury surface that does not absorb fixed air. His introduction was very enlightening to scientists who studied gases at that time. Cavendish measured that fixed air was 1.57 times heavier than ordinary air, measured the weight of fixed air discharged by acid in limestone, marble, pearl ash and other substances, and calculated the content of fixed air in these substances. He also found that in ordinary air, if the content of fixed air accounts for 1/9 of the total volume, the burning candle will be extinguished in it. These experimental studies have made people know more about the properties of carbon dioxide. Before cavendish, many people had produced hydrogen, but they didn't study it seriously. Cavendish used dilute sulfuric acid or dilute hydrochloric acid to react with zinc or iron to obtain hydrogen. It was found that it burned immediately after ignition, and it was insoluble in water and alkali. It was 1 1 times lighter than ordinary air and different from other known gases, so it was concluded that it was a new gas. He also found that the amount of hydrogen released by a certain amount of metal interacting with dilute acid has nothing to do with the kind and concentration of acid, but varies with different metals. Cavendish believed in phlogiston at that time and thought that hydrogen was phlogiston. It happened that many phlogiston speculated that phlogiston had a negative weight. The balloon filled with hydrogen slowly lifted off, which encouraged phlogiston, and their guess seemed to be confirmed. But careful Cavendish discovered the buoyancy principle of air and measured the weight of hydrogen with accurate experiments, thus denying the view that phlogiston has negative weight. Although he believes in phlogiston, he respects the facts of scientific experiments more. Since 177 1, cavendish has devoted himself to the experimental study of electricity, which is a systematic and lasting research topic. It was not until 178 1 that priestley made a new discovery on a research topic explored by Cavendish that Cavendish returned to the study of gas. 178 1 year, priestley claimed that he had done a "clueless" experiment: he mixed the hydrogen discovered by Cavendish with the dephosphorized air (that is, oxygen) he found in a closed bottle, then exploded it with an electric spark, and found that dew was formed in the bottle. He doubted the result of his experiment and could not explain it. When priestley told this to cavendish, it aroused the latter's interest. With priestley's permission, cavendish continued the experiment. Because the experiment he designed was more accurate, he quickly came to a conclusion. In his paper "Experiment on Air" published in 1784, he pointed out that the mixture of hydrogen and ordinary air exploded, and almost all hydrogen and 1/5 ordinary air condensed into dew, which is water. He also did many experiments with oxygen instead of ordinary air and obtained water. He also proved that the total volume of hydrogen and oxygen is 2.02: 1. From this, he confirmed that water is composed of hydrogen and oxygen. In the above experiment, Cavendish encountered two unexpected problems. He found that when the mixed gas of hydrogen and oxygen explodes, sometimes the water produced is a little acidic, which can be neutralized with alkali and then evaporated to get a small amount of saltpeter. If there is more oxygen, more acid will be produced; If there is too much hydrogen, no acid will be produced. Why is this? To this end, he continued to do a series of experiments and finally solved the problem. He pointed out in the paper published in 1785 that the sour taste of water is because it contains nitric acid or nitrous acid, which is formed by the mixture of oxygen and nitrogen. At the high temperature of electric spark explosion, oxygen and nitrogen will combine. When hydrogen is mixed with ordinary air, the reaction temperature is not high enough because of the existence of a large amount of nitrogen, so nitric acid cannot be generated. This fine experiment provides people with a method to make nitric acid from the air. Cavendish also found that nitric acid or nitrous acid after explosion reaction was neutralized by potash solution, and after excess oxygen was absorbed by sulfide solution, a small bubble remained in the test tube, the volume of which was about1120 of the total volume of nitrogen. The nature of this gas is different from nitrogen. Does not participate in chemical reactions at all. What is it? Cavendish can't explain. However, he put forward a research topic for future generations. It was not until 100 years later that British chemists Rayleigh and Ramsey confirmed that this part of the gas was inert. Cavendish's paper published in 1767 has also attracted people's attention. This paper introduces his experiments on water and fixed air. Boiling the well water of a deep well, it is found that fixed air escapes and white precipitate is produced at the same time. He thinks that white sediments and fixed air are originally soluble in water, and they may be calcareous soil soluble in water. To prove this point, he introduced fixed air into clear limewater, which initially produced milky white precipitate. After the fixed air is continuously introduced, the precipitate is dissolved again and the solution is clear and bright again. At this time, he boiled the solution and immediately released fixed air like well water, and produced white precipitate. Cavendish's experiment and his explanation made people realize a universal natural phenomenon. In limestone-covered areas, rainwater or spring water containing carbon dioxide flows through limestone strata, slowly dissolving part of limestone to form bicarbonate solution. When these solutions drip slowly in rocks, carbon dioxide may escape accidentally due to temperature changes or evaporation of water vapor, and calcium carbonate crystals will precipitate over time, gradually forming strange scenes such as Zhong Shi milk and right bamboo shoots. There is a scientific explanation for karst landforms. Cavendish published his first paper in 1766, which began to attract social attention. Later, he published some fruitful reports on chemistry and physics, which gradually shocked the scientific community in Britain and even Europe. At that time, some people expressed doubts. Therefore, the Royal Society organized a committee to repeat Cavendish's experiment, and the results completely confirmed Cavendish's excellent experimental skills and his honest attitude towards science. Cavendish is a great scientist and has won the respect of the scientific community. Cavendish worships Newton very much. He not only absorbed the power of devoting himself to science from Newton, but also accepted many research projects from Newton. He studied dynamics according to the law of universal gravitation; According to Newton's viewpoint that heat is particle vibration, many experiments on heat have been done and a method for measuring specific heat has been found. He also used the law of gravity to determine that the density of the earth is 5.5 times that of water, from which the relative weight of the earth can be calculated. These famous experiments not only verified the scientific nature of the law of universal gravitation, but also showed that Cavendish had a solid mathematical foundation and superb experimental skills. Cavendish is engaged in scientific research, seeking neither fame nor profit. When many people praised him for discovering hydrogen, he said modestly, "This matter has been noticed by others." Many of his papers and experimental reports were not published in a hurry, especially many discourses on natural philosophy were basically unpublished. Perhaps because of his caution, perhaps because of his shyness, most of the manuscripts he thought were not published. Therefore, in his nearly 50 years of scientific research career, he did not write a book, which is a pity to promote the development of scientific research. Although Cavendish lived alone all his life, the new world opened up by scientific research institutes provided him with special interest. Although he was weak since childhood, his life has always been very regular, so he seldom gets sick. He didn't die until March of 18 10 at the age of 79.