科学家百人箓 (one hundred most influential scientists of all times)

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有观点认为牛顿本人对他自己的成就非常谦逊，1676年，在他写给罗伯特·胡克的一封信中出现了一句名言：
“        如果我比别人看得更远，那是因为我站在巨人的肩上        ”
(zh.wikipedia.org/艾萨克·牛顿)
它出现在2010年的邮戳中。正好盖在牛顿极限明信片上。
法国和其他国家邮票的牛顿极限明信片很常见，但罕见的是英国邮票的极限明信片。

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卡尔·冯·林奈（瑞典語：Carl von Linné，1707年5月23日－1778年1月10日），也譯為林内，受封貴族前名为卡尔·林奈乌斯（Carl Linnaeus），由于瑞典学者阶层的姓常拉丁化，又作卡罗卢斯·林奈烏斯（拉丁語：Carolus Linnaeus），瑞典植物学家、动物学家和医生，瑞典科学院创始人之一，並且担任第一任主席，他也是智人的正模标本。他奠定了现代生物学命名法二名法的基础，是现代生物分类学之父，也被认为是现代生态学之父之一。他的很多著作使用拉丁文撰写，他的名字在拉丁语中寫作Carolus Linnæus（在1761年之后作Carolus a Linné）。

林奈身處的世紀，也正是歐洲的大航海世紀，許多航海歸來的生物學家和博物學家帶回世界各地的動植物，並用自己的喜好為之命名，造成一物多名，或异物同名的混亂現象。

林奈在烏普薩拉大學其間，发现花的花粉囊和雌蕊可以被作为植物分类的基础。他将此发现写成一篇短论文。这个发现为他提供了一个非常教授的职位。1732年乌普萨拉科学院资助他去瑞典北部的拉普兰考察。到那个时候为止，欧洲人对拉普兰还一无所知，在這4600英里的土地上，林奈發現100多種新種植物，1737年林奈将他对拉普兰植物世界的考察写成一本书发表，在這本書中，林奈首次發表了以植物生殖器官進行分類的方法。

1753年林奈發表《植物種誌》（Species Plantarum），採用雙名法，以拉丁文來為生物命名，其中第一个名字是属的名字，第二个是种的名字，屬名為名詞，種名為形容詞，形容些物種的特性，或可加上發現者的名字，以紀念這位發現者，也有負責的意思。林奈用這種方法幫植物命名，後來他也用同樣的方法為動物命名，此種命名法也一直延用至今。

此后林奈开始了他对欧洲大陆的科学访问。在荷兰时他第一次将他的分类学手稿《自然系統》（Systema Naturae）给别人看。其中他放弃了过去混淆不清的命名法，引进了一直沿用至今的双名法如“Homo sapiens”。属以上的分类也被给予清晰的定义。(zh.wikipedia.org/卡尔·林奈)

Swedish naturalist and explorer Carolus Linnaeus was the first to frame principles for defining natural genera and species of organisms and to create a uniform system for naming them (binomial nomenclature).  

The “Sexual System” of Classification
In 1735 Linnaeus published Systema Naturae (“The System of Nature”), a folio volume of only 11 pages, which presented a hierarchical classification, or taxonomy, of the three kingdoms of nature: stones, plants, and animals. Each kingdom was subdivided into classes, orders, genera, species, and varieties. This hierarchy of taxonomic ranks replaced traditional systems of biological classification that were based on mutually exclusive divisions, or dichotomies.
In particular, it was the botanical section of Systema Naturae that built Linnaeus’s scientific reputation. After reading essays on sexual reproduction in plants by Vaillant and by German botanist Rudolph Jacob Camerarius, Linnaeus had become convinced of the idea that all organisms reproduce sexually. As a result, he expected each plant to possess male and female sexual organs (stamens and pistils), or “husbands and wives,” as he also put it. On this basis, he designed a simple system of distinctive characteristics to classify each plant. The number and position of the stamens, or husbands, determined the class to which it belonged, whereas the number and position of pistils, or wives, determined the order. This “sexual system,” as Linnaeus called it, became extremely popular.

Classification by “Natural Characters”
In 1736 Linnaeus, then in the Netherlands, published a booklet, the Fundamenta Botanica (“The Foundations of Botany”), that framed the principles and rules to be followed in the classification and naming of plants. The year before, Linnaeus was introduced to George Clifford, a local English merchant and banker who had close connections to the Dutch East India Company. Impressed by Linnaeus’s knowledge, Clifford offered Linnaeus a position as curator of his botanical garden. Linnaeus accepted the position and used this opportunity to expand certain chapters of the Fundamenta Botanica in separate publications: the Bibliotheca Botanica (1736; “The Library of Botany”); Critica Botanica (1737; “A Critique of Botany”), on botanical nomenclature; and Classes Plantarum (1738; “Classes of Plants”). He applied the theoretical framework laid down in these books in two further publications: Hortus Cliffortianus (1737), a catalogue of the species contained in Clifford’s collection; and the Genera Plantarum (1737; “Genera of Plants”), which modified and updated definitions of plant genera first offered by Joseph Pitton de Tournefort.
Genera Plantarum was considered by Linnaeus to be his crowning taxonomic achievement. In contrast to earlier attempts by other botanists at generic definition, which proceeded by a set of arbitrary divisions, Genera Plantarum presented a system based on what Linnaeus called the “natural characters” of genera—morphological descriptions of all the parts of flower and fruit. In contrast to systems based on arbitrary divisions (including his own sexual system), a system based on natural characters could accommodate the growing number of new species—often possessing different morphological features—pouring into Europe from its oversea trading posts and colonies.
Linnaeus’s distinction between artificial and natural classifications of organisms, however, raised the question of the mechanism that allowed organisms to fall into natural hierarchies. He could only answer this question with regard to species: species, according to Linnaeus, were similar in form because they derived from the same parental pair created by God at the beginning of the world. Linnaeus tried to explain the existence of natural genera, orders, or classes within the context of hybridization; however, the question of natural hierarchies would not receive a satisfying answer until English naturalist Charles Darwin explained similarity by common descent in his Origin of Species (1859).

Binomial Nomenclature
In 1738 Linnaeus began a medical practice in Stockholm, Sweden, which he maintained until 1742, when he received the chair in medicine and botany at Uppsala University. Linnaeus built his further career upon the foundations he laid in the Netherlands. Linnaeus used the international contacts to create a network of correspondents that provided him with seeds and specimens from all over the world. He then incorporated this material into the botanical garden at Uppsala, and these acquisitions helped him develop and refine the empirical basis for revised and enlarged editions of his major taxonomic works. During his lifetime he completed 12 editions of the Systema Naturae, six editions of the Genera Plantarum, two editions of the Species Plantarum (“Species of Plants,” which succeeded the Hortus Cliffortianus in 1753), and a revised edition of the Fundamenta Botanica (which was later renamed the Philosophia Botanica [1751; “Philosophy of Botany”]).
Linnaeus’s most lasting achievement was the creation of binomial nomenclature, the system of formally classifying and naming organisms according to their genus and species. In contrast to earlier names that were made up of diagnostic phrases, binomial names (or “trivial” names as Linnaeus himself called them) conferred no prejudicial information about the plant species named. Rather, they served as labels by which a species could be universally addressed. This naming system was also implicitly hierarchical, as each species is classified within a genus. The first use of binomial nomenclature by Linnaeus occurred within the context of a small project in which students were asked to identify the plants consumed by different kinds of cattle. In this project, binomial names served as a type of shorthand for field observations. Despite the advantages of this naming system, binomial names were used consis- tently in print by Linnaeus only after the publication of the Species Plantarum (1753).
The rules of nomenclature that Linnaeus put forward in his Philosophia Botanica rested on a recognition of the “law of priority,” the rule stating that the first properly published name of a species or genus takes precedence over all other proposed names. These rules became firmly established in the field of natural history and also formed the backbone of international codes of nomenclature— such as the Strickland Code (1842)—created for the fields of botany and zoology in the mid-19th century. The first edition of the Species Plantarum (1753) and the 10th edition of the Systema Naturae (1758) are the agreed starting points for botanical and zoological nomenclature, respectively.

Other Contributions
Toward the end of his life, Linnaeus became interested in other aspects of the life sciences. Of greatest influence were his physico-theological writings, Oeconomia Naturae (1749; “The Economy of Nature”) and Politiae Naturae (1760; “The Politics of Nature”). Both works were of great importance to Charles Darwin. His studies of plant hybridization influenced the experimental tradition that led directly to the pea plant experiments of Austrian botanist Gregor Mendel.

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亨利·卡文迪什（英語：Henry Cavendish，又译亨利·卡文迪许、亨利·卡文狄西、亨利·卡文迪西，1731年10月10日－1810年2月24日），英国物理学家、化学家。他首次对氢气的性质进行了细致的研究，证明了水并非单质，预言了空气中稀有气体的存在。他首次发现了库伦定律和欧姆定律，将电势概念广泛应用于电学，并精确测量了地球的密度，被认为是牛顿之后英国最伟大的科学家之一。(zh.wikipedia.org/亨利·卡文迪什)

Henry Cavendish was a natural philosopher and is considered to be the greatest experimental and theoretical English chemist and physicist of his age. Cavendish was distinguished for great accuracy and precision in researches into the composition of atmospheric air, the properties of different gases, the synthesis of water, the law governing electrical attraction and repulsion, a mechanical theory of heat, and calculations of the density (and hence the weight) of the Earth. His experiment to weigh the Earth has come to be known as the Cavendish experiment.

Research in Chemistry
Cavendish was a shy man who was uncomfortable in society and avoided it when he could. About the time of the times of his father’s death, Cavendish began to work closely with Charles Blagden, an association that helped Blagden enter fully into London’s scientific society. In return, Blagden helped to keep the world at a distance from Cavendish. Cavendish published no books and few papers, but he achieved much. Several areas of research, including mechanics, optics, and magnetism, feature extensively in his manuscripts, but they scarcely feature in his published work.
His first publication (1766) was a combination of three short chemistry papers on “factitious airs,” or gases produced in the laboratory. He produced “inflammable air” (hydrogen) by dissolving metals in acids and “fixed air” (carbon dioxide) by dissolving alkalis in acids, and he collected these and other gases in bottles inverted over water or mercury. He then measured their solubility in water and their specific gravity and noted their combustibility. Cavendish was awarded the Royal Society’s Copley Medal for this paper. Gas chemistry was of increasing importance in the latter half of the 18th century and became crucial for Frenchman Antoine-Laurent Lavoisier’s reform of chemistry, generally known as the chemical revolution.
In 1783 Cavendish published a paper on eudiometry (the measurement of the goodness of gases for breathing). He described a new eudiometer of his own invention, with which he achieved the best results to date, using what in other hands had been the inexact method of measuring gases by weighing them. He next published a paper on the production of water by burning inflammable air (that is, hydrogen) in dephlogisticated air (now known to be oxygen), the latter a constituent of atmospheric air. Cavendish concluded that dephlogisticated air was dephlogisticated water and that hydrogen was either pure phlogiston or phlogisticated water. He reported these findings to Joseph Priestley, an English clergyman and scientist, no later than March 1783, but did not publish them until the following year.
The Scottish inventor James Watt published a paper on the composition of water in 1783; Cavendish had performed the experiments first but published second. Controversy about priority ensued. In 1785 Cavendish carried out an investigation of the composition of common (i.e., atmospheric) air, obtaining, as usual, impressively accurate results. He observed that, when he had determined the amounts of phlogisticated air (nitrogen) and dephlogisticated air (oxygen), there remained a volume of gas amounting to 1/120 of the original volume of common air.
In the 1890s, two British physicists, William Ramsay and Lord Rayleigh, realized that their newly discovered inert gas, argon, was responsible for Cavendish’s problematic residue; he had not made an error. What he had done was perform rigorous quantitative experiments, using standardized instruments and methods, aimed at reproducible results; taken the mean of the result of several experiments; and identified and allowed for sources of error.
Cavendish, as noted before, used the language of the old phlogiston theory in chemistry. In 1787 he became one of the earliest outside France to convert to the new antiphlogistic theory of Lavoisier, though he remained skeptical about the nomenclature of the new theory. He also objected to Lavoisier’s identification of heat as having a material or elementary basis. Working within the frame- work of Newtonian mechanism, Cavendish had tackled the problem of the nature of heat in the 1760s, explaining heat as the result of the motion of matter. In 1783 he published a paper on the temperature at which mercury freezes and in that paper made use of the idea of latent heat, although he did not use the term because he believed that it implied acceptance of a material theory of heat. He made his objections explicit in his 1784 paper on air. He went on to develop a general theory of heat, and the manuscript of that theory has been persuasively dated to the late 1780s. His theory was at once mathematical and mechanical; it contained the principle of the conservation of heat (later understood as an instance of conservation of energy) and even contained the concept (although not the label) of the mechanical equivalent of heat.

Experiments with Electricity
Cavendish also worked out a comprehensive theory of electricity. Like his theory of heat, this theory was mathematical in form and was based on precise quantitative experiments. In 1771 he published an early version of his theory, based on an expansive electrical fluid that exerted pressure. He demonstrated that if the intensity of electric force was inversely proportional to distance, then the electric fluid in excess of that needed for electrical neutrality would lie on the outer surface of an electrified sphere; and he confirmed this experimentally. Cavendish continued to work on electricity after this initial paper, but he published no more on the subject.
Beginning in the mid-1780s Cavendish carried out most of his experiments at his house in London. The most famous of those experiments, published in 1798, was to determine the density of the Earth. His apparatus for weighing the world was a modification of the Englishman John Michell’s torsion balance. The balance had two small lead balls suspended from the arm of a torsion balance and two much larger stationary lead balls. Cavendish calculated the attraction between the balls from the period of oscillation of the torsion balance, and then he used this value to calculate the density of the Earth. What was extraordinary about Cavendish’s experiment was its elimination of every source of error and every factor that could disturb the experiment and its precision in measuring an astonishingly small attraction, a mere 1/50,000,000 of the weight of the lead balls. The result that Cavendish obtained for the density of the Earth is within 1 percent of the currently accepted figure.
The combination of painstaking care, precise experimen- tation, thoughtfully modified apparatus, and fundamental theory carries Cavendish’s unmistakable signature. It is fitting that the University of Cambridge’s great physics laboratory is named the Cavendish Laboratory.

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约瑟夫·普利斯特里（英語：Joseph Priestley，1733年3月13日－1804年2月6日），18世紀英国的自然哲学家、化学家、牧师、教育家和自由政治理论家。出版过150部以上的著作，对气体特别是氧气的早期研究做出过重要贡献，但由于他坚持燃素说的理论，使其未成为化学革命的先驱者。(zh.wikipedia.org/约瑟夫·普利斯特里)

English clergyman, political theorist, and physical scientist Joseph Priestley contributed to advances in liberal political and religious thought and in experimental chemistry. He is best remembered for his contribution to the chemistry of gases.

Work in Electricity
In 1765 Priestley met the American scientist and statesman Benjamin Franklin, who encouraged him to publish The History and Present State of Electricity, with Original Experiments (1767). In this work, Priestley used history to show that scientific progress depended more on the accumulation of “new facts” that anyone could discover than on the theoretical insights of a few men of genius. This view shaped Priestley’s electrical experiments, in which he anticipated the inverse square law of electrical attraction, discovered that charcoal conducts electricity, and noted the relationship between electricity and chemical change.

The Chemistry of Gases
In 1767 Priestley began intensive experimental investigations into chemistry. Between 1772 and 1790, he published six volumes of Experiments and Observations on Different Kinds of Air and more than a dozen articles in the Royal Society’s Philosophical Transactions describing his experiments on gases, or “airs,” as they were then called. British pneumatic chemists had previously identified three types of gases: air, carbon dioxide (fixed air), and hydrogen (inflammable air). Priestley incorporated an explanation of the chemistry of these gases into the phlogiston theory, according to which combustible substances released phlogiston (an immaterial “principle of inflammability”) during burning.
Priestley discovered 10 new gases: nitric oxide (nitrous air), nitrogen dioxide (red nitrous vapour), nitrous oxide (inflammable nitrous air, later called “laughing gas”), hydrogen chloride (marine acid air), ammonia (alkaline air), sulfur dioxide (vitriolic acid air), silicon tetrafluoride (fluor acid air), nitrogen (phlogisticated air), oxygen (dephlogisticated air, independently codiscovered by Carl Wilhelm Scheele), and a gas later identified as carbon monoxide. Priestley’s experimental success resulted predominantly from his ability to design ingenious apparatuses and his skill in their manipulation. He gained particular renown for an improved pneumatic trough in which, by collecting gases over mercury instead of in water, he was able to isolate and examine gases that were soluble in water. For his work on gases, Priestley was awarded the Royal Society’s prestigious Copley Medal in 1773. Upon contemplating the processes of vegetation and the “agitation” of seas and lakes, Priestley envisioned the means by which a benevolent nature restored the “common air” that had been “vitiated and diminished” by such “noxious” processes as combustion and respiration. Apart from strengthening his own spiritual views, these observations informed the photosynthesis experiments performed by his contemporaries, the Dutch physician Jan Ingenhousz and the Swiss clergyman and naturalist Jean Senebier.
When confronted by the multitude of diseases that plagued the growing populations in towns and military installations, Priestley designed an apparatus that produced carbonated water, a mixture that he thought would provide medicinal benefit to sufferers of scurvy and vari- ous fevers. Although it ultimately proved ineffective in treating these disorders, the “gasogene” that employed this technique later made possible the soda-water industry. Priestley also designed the “eudiometer,” which was used in the general movement for sanitary reform and urban design to measure the “purity” (oxygen content) of atmospheric air.

The Discovery of Oxygen and the Chemical Revolution
Priestley’s lasting reputation in science is founded upon the discovery he made on Aug. 1, 1774, when he obtained a colourless gas by heating red mercuric oxide. Finding that a candle would burn and that a mouse would thrive in this gas, he called it “dephlogisticated air,” based upon the belief that ordinary air became saturated with phlogiston once it could no longer support combustion and life. Priestley was not yet sure, however, that he had discovered a “new species of air.” The following October, while in Paris on a journey through Europe, he informed the French chemist Antoine-Laurent Lavoisier how he obtained the new “air.” This meeting between the two scientists was highly significant for the future of chemistry. Lavoisier immediately repeated Priestley’s experiments and, between 1775 and 1780, conducted intensive investigations from which he derived the elementary nature of oxygen, recognized it as the “active” principle in the atmosphere, interpreted its role in combustion and respiration, and gave it its name. Lavoisier’s pronouncements of the activity of oxygen revolutionized chemistry.
In 1800 Priestley published a slim pamphlet, Doctrine of Phlogiston Established, and That of the Composition of Water Refuted, which he expanded to book length in 1803. The Doctrine of Phlogiston provided a detailed account of what he envisioned to be the empirical, theoretical, and methodological shortcomings of the oxygen theory. Priestley called for a patient, humble, experimental approach to God’s infinite creation. Chemistry could support piety and liberty only if it avoided speculative theorizing and encouraged the observation of God’s benevolent creation. The phlogiston theory was superseded by Lavoisier’s oxi- dation theory of combustion and respiration.

Turmoil and Exile
The English press and government decreed that Priestley’s support, together with that of his friend, the moral philosopher Richard Price, of the American and French Revolutions was “seditious.” On July 14, 1791, the “Church-and-King mob” destroyed Priestley’s house and laboratory. Priestley and his family retreated to the security of Price’s congregation at Hackney, near London. Priestley later began teaching at New College, Oxford, and defended his anti-British government views in Letters to the Right Honourable Edmund Burke (1791).
In 1794 Priestley fled to the United States, where he discovered a form of government that was “relatively tolerable.” His best-known writing in the United States, Letters to the Inhabitants of Northumberland (1799), became part of the Republican response to the Federalists. Priestley died at Northumberland, Pennsylvania, mourned and revered by Thomas Jefferson, the third president of the United States.

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路易吉·阿罗西奥·伽伐尼（意大利文：Luigi Aloisio Galvani, 拉丁文：Aloysius Galvani）1737年9月9日－1798年12月4日）是意大利醫生、物理學家与哲学家，現代產科學的先驅者。他在意大利博洛尼亞出生和逝世。在1780年，他發現死青蛙的腿部肌肉接觸电火花時會顫動，從而發現神經元和肌肉會產生電力。他是第一批涉足生物电领域研究的人物之一，这一领域在今天仍然在研究神经系统的电信号和电模式。(zh.wikipedia.org/路易吉·伽伐尼)

Luigi Galvani was an Italian physician and physicist who investigated the nature and effects of what he conceived to be electricity in animal tissue. His discoveries led to the invention of the voltaic pile, a kind of battery that makes possible a constant source of current electricity.

Early Years
Galvani followed his father’s preference for medicine by attending the University of Bologna, graduating in 1759. On obtaining the doctor of medicine degree, with a thesis (1762) De ossibus on the formation and development of bones, he was appointed lecturer in anatomy at the University of Bologna and professor of obstetrics at the separate Institute of Arts and Sciences. Beginning with his doctoral thesis, his early research was in comparative anatomy—such as the structure of renal tubules, nasal mucosa, and the middle ear—with a tendency toward physiology, a direction appropriate to the later work for which he is noted.
Galvani’s developing interest was indicated by his lectures on the anatomy of the frog in 1773 and in electrophysiology in the late 1770s, when, following the acquisition of an electrostatic machine (a large device for making sparks) and a Leyden jar (a device used to store static electricity), he began to experiment with muscular stimulation by electrical means. His notebooks indicate that, from the early 1780s, animal electricity remained his major field of investigation. Numerous ingenious observa- tions and experiments have been credited to him; in 1786, for example, he obtained muscular contraction in a frog by touching its nerves with a pair of scissors during an electrical storm. He also observed the legs of a skinned frog kick when a scalpel touched a lumbar nerve of the animal while an electrical machine was activated.
Galvani assured himself by further experiments that the twitching was, in fact, related to the electrical action. He also elicited twitching without the aid of the electrostatic machine by pressing a copper hook into a frog’s spinal cord and hanging the hook on an iron railing. Although twitching could occur during a lightning storm or with the aid of an electrostatic machine, it also occurred with only a metallic contact between leg muscles and nerves leading to them. A metallic arc connecting the two tissues could therefore be a substitute for the electrostatic machine.

Electrical Nature of Nerve Impulse
Galvani delayed the announcement of his findings until 1791, when he published his essay De Viribus Electricitatis in Motu Musculari Commentarius (Commentary on the Effect of Electricity on Muscular Motion). He concluded that animal tissue contained a heretofore neglected innate, vital force, which he termed “animal electricity,” which activated nerve and muscle when spanned by metal probes. He believed that this new force was a form of electricity in addition to the “natural” form that is produced by lightning or by the electric eel and torpedo ray and to the “artificial” form that is produced by friction (i.e., static electricity). He consid- ered the brain to be the most important organ for the secretion of this “electric fluid” and the nerves to be conductors of the fluid to the nerve and muscle, the tissues of which act as did the outer and inner surfaces of the Leyden jar. The flow of this electric fluid provided a stimulus for the irritable muscle fibres, according to his explanation.
Galvani’s scientific colleagues generally accepted his views, but Alessandro Volta, the outstanding professor of physics at the University of Pavia, was not convinced by the analogy between the muscle and the Leyden jar. Deciding that the frog’s legs served only as an indicating electroscope, he held that the contact of dissimilar metals was the true source of stimulation; he referred to the electricity so generated as “metallic electricity” and decided that the muscle, by contracting when touched by metal, resembled the action of an electroscope. Furthermore, Volta said that, if two dissimilar metals in contact both touched a muscle, agitation would also occur and increase with the dissimilarity of the metals. Thus Volta rejected the idea of an “animal electric fluid,” replying that the frog’s legs responded to differences in metal temper, composition, and bulk. Galvani refuted this by obtaining muscular action with two pieces of the same material. Galvani’s gen- tle nature and Volta’s high principles precluded any harshness between them. Volta, who coined the term galvanism, said of Galvani’s work that “it contains one of the most beautiful and most surprising discoveries.”
In retrospect, Galvani and Volta are both seen to have been partly right and partly wrong. Galvani was correct in attributing muscular contractions to an electrical stimulus but wrong in identifying it as an “animal electricity.” Volta correctly denied the existence of an “animal electricity” but was wrong in implying that every electrophysiological effect requires two different metals as sources of current.
Galvani, shrinking from the controversy over his discovery, continued his work as teacher, obstetrician, and surgeon, treating both wealthy and needy without regard to fee. In 1794 he offered a defense of his position in an anonymous book, Dell’uso e dell’attività dell’arco conduttore nella contrazione dei muscoli (“On the Use and Activity of the Conductive Arch in the Contraction of Muscles”), the supplement of  which described muscular contraction without the need of any metal. He caused a muscle to con- tract by touching the exposed muscle of one frog with a nerve of another and thus established for the first time that bioelectric forces exist within living tissue.
Galvani provided the major stimulus for Volta to dis- cover a source of constant current electricity; this was the voltaic pile, or a battery, with its principles of operation combined from chemistry and physics. This discovery led to the subsequent age of electric power. Moreover, Galvani opened the way to new research in the physiology of muscle and nerve and to the entire subject of electrophysiology.  

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弗里德里希·威廉·赫歇爾爵士，FRS，KH（德語：Friedrich Wilhelm Herschel，英語：Frederick William Herschel，1738年11月15日－1822年8月25日），出生於德國漢諾威，英國天文學家及音樂家，曾作出多項天文發現，包括天王星等。被譽為「恆星天文學之父」。(zh.wikipedia.org/威廉·赫歇爾)

German-born British astronomer Sir William Herschel was the founder of sidereal astronomy for the systematic observation of the heavens. He discovered the planet Uranus, hypothesized that nebulae are composed of stars, and developed a theory of stellar evolution. He was knighted in 1816.

Discovery of Uranus
The intellectual curiosity that Herschel acquired from his father led him from the practice to the theory of music, which he studied in Robert Smith’s Harmonics. From this book he turned to Smith’s A Compleat System of Opticks, which introduced him to the techniques of telescope construction. Herschel soon began to grind his own mirrors. They were ground from metal disks of copper, tin, and antimony in various proportions. He later produced large mirrors of superb quality—his telescopes proved far superior even to those used at the Greenwich Observatory. He also made his own eyepieces, the strongest with a magnifying power of 6,450 times. Herschel’s largest instrument, too cumbersome for regular use, had a mirror made of speculum metal, with a diameter of 122 centimetres (48 inches) and a focal length of 12 metres (40 feet). Completed in 1789, it became one of the technical wonders of the 18th century.
In 1781, during his third and most complete survey of the night sky, Herschel came upon an object that he realized was not an ordinary star. It proved to be the planet Uranus, the first planet to be discovered since prehistoric times. Herschel became famous almost overnight. His friend Dr. William Watson, Jr., introduced him to the Royal Society of London, which awarded him the Copley Medal for the discovery of Uranus, and elected him a Fellow. He was subsequently appointed as an astronomer to George III.
Herschel’s big telescopes were ideally suited to study the nature of nebulae, which appear as luminous patches in the sky. Some astronomers thought they were nothing more than clusters of innumerable stars the light of which blends to form a milky appearance. Others held that some nebulae were composed of a luminous fluid. However, Herschel found that his most powerful telescope could resolve into stars several nebulae that appeared “milky” to less well equipped observers. He was convinced that other nebulae would eventually be resolved into individual stars with more powerful instruments. This encouraged him to argue in 1784 and 1785 that all nebulae were formed of stars and that there was no need to postulate the existence of a mysterious luminous fluid to explain the observed facts. Nebulae that could not yet be resolved must be very distant systems, he maintained; and, since they seem large to the observer, their true size must indeed be vast—possibly larger even than the star system of which the Sun is a member. By this reasoning, Herschel was led to postulate the existence of what later were called “island universes” of stars.

Theory of the Evolution of Stars
In order to interpret the differences between these star clusters, Herschel emphasized their relative densities by contrasting a cluster of tightly packed stars with others in which the stars were widely scattered. These formations showed that attractive forces were at work. In other words, a group of widely scattered stars was at an earlier stage of its development than one whose stars were tightly packed. Thus, Herschel made change in time, or evolution, a fundamental explanatory concept in astronomy.
In 1785 Herschel developed a cosmogony—a theory concerning the origin of the universe: the stars originally were scattered throughout infinite space, in which attrac- tive forces gradually organized them into even more fragmented and tightly packed clusters. Turning then to the system of stars of which the Sun is part, he sought to determine its shape on the basis of two assumptions: (1) that with his telescope he could see all the stars in the sys- tem, and (2) that within the system the stars are regularly spread out. Both of these assumptions he subsequently had to abandon. But in his studies he gave the first major example of the usefulness of stellar statistics in that he could count the stars and interpret this data in terms of the extent in space of the Galaxy’s star system.

Theory of the Structure of Nebulae
On Nov. 13, 1790, Herschel observed a remarkable nebula, which he was forced to interpret as a central star surrounded by a cloud of “luminous fluid.” This discovery contradicted his earlier views. Hitherto Herschel had reasoned that many nebulae that he was unable to resolve (separate into distinct stars), even with his best telescopes, might be distant “island universes” (such objects are now known as galaxies). He was able, however, to adapt his earlier theory to this new evidence by concluding that the central star he had observed was condensing out of the surrounding cloud under the forces of gravity. In 1811 he extended his cosmogony backward in time to the stage when stars had not yet begun to form out of the fluid.
In dealing with the structural organization of the heavens, Herschel assumed that all stars were equally bright, so that differences in apparent brightness are an index only of differences in distances. Throughout his career he stubbornly refused to acknowledge the accumulating evidence that contradicted this assumption. Herschel’s labours through 20 years of systematic sweeps for nebulae (1783–1802) resulted in three catalogs listing 2,500 nebulae and star clusters that he substituted for the 100 or so milky patches previously known. He also cataloged 848 double stars—pairs of stars that appear close together in space, and measurements of the comparative brightness of stars. He observed that double stars did not occur by chance as a result of random scattering of stars in space but that they actually revolved about each other. His 70 published papers include not only studies of the motion of the solar system through space and the announcement in 1800 of the discovery of infrared rays but also a succession of detailed investigations of the planets and other members of the solar system.

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安托万-洛朗·德·拉瓦锡（法語：Antoine-Laurent de Lavoisier，1743年8月26日－1794年5月8日），法国貴族，著名化学家、生物学家，被後世尊稱為“近代化學之父l。他使化学从定性转为定量，給出了氧與氫的命名，並且預測了硅的存在。他幫助建立了公制。拉瓦锡提出了「元素」的定義，按照這定義，於1789年發表第一個現代化學元素列表，列出33種元素，其中包括光與熱和一些當時被認為是元素的化合物。拉瓦锡的貢獻促使18世紀的化學更加物理及數學化。他提出规范的化学命名法，撰写了第一部真正現代化学教科书《化學基本論述》（Traité élémentaire de Chimie）。他倡导并改进定量分析方法并用其验证了质量守恒定律。他創立氧化说以解释燃烧等实验现象，指出动物的呼吸实质上是缓慢氧化。这些划时代贡献使得他成为历史上最伟大的化学家之一。拉瓦锡不幸在法国大革命中被送上断头台而死。(zh.wikipedia.org/安托万-洛朗·德·拉瓦锡)

Antoine-Laurent Lavoisier was a prominent French chemist and leading figure in the 18th-century chemical revolution who developed an experimentally based theory of the chemical reactivity of oxygen and coau- thored the modern system for naming chemical substances. Having also served as a leading financier and public admin- istrator before the French Revolution, he was executed with other financiers during the revolutionary terror.

Pneumatic Chemistry
The chemistry Lavoisier studied as a student was not a subject particularly noted for conceptual clarity or  theoretical rigour. Although chemical writings contained considerable information about the substances chemists studied, little agreement existed upon the precise composition of chemical elements or between explanations of changes in composition. Many natural philosophers still viewed the four elements of Greek natural philosophy— earth, air, fire, and water—as the primary substances of all matter. Chemists like Lavoisier focused their attention upon analyzing “mixts” (i.e., compounds), such as the salts formed when acids combine with alkalis. They hoped that by first identifying the properties of simple substances they would then be able to construct theories to explain the properties of compounds.
Pneumatic chemistry was a lively subject at the time Lavoisier became interested in a particular set of problems that involved air: the linked phenomena of combustion, respiration, and what 18th-century chemists called calcination (the change of metals to a powder [calx], such as that obtained by the rusting of iron).

Conservation of Mass
The assertion that mass is conserved in chemical reactions was an assumption of Enlightenment investigators rather than a discovery revealed by their experiments. Lavoisier believed that matter was neither created nor destroyed in chemical reactions, and in his experiments he sought to demonstrate that this belief was not violated. Still he had difficulty proving that his view was universally valid. His insistence that chemists accepted this assumption as a law was part of his larger program for raising chemistry to the investigative standards and causal explanation found in contemporary experimental physics.
While other chemists were also looking for conserva- tion principles capable of explaining chemical reactions, Lavoisier was particularly intent on collecting and weigh- ing all the substances involved in the reactions he studied. His success in the many elaborate experiments he con- ducted was in large part due to his independent wealth, which enabled him to have expensive apparatus built to his design, and to his ability to recruit and direct talented research associates. Today the conservation of mass is still sometimes taught as “Lavoisier’s law,” which is indicative of his success in making this principle a foundation of modern chemistry.

Phlogiston Theory
After being elected a junior member of the Academy of Sciences, Lavoisier began searching for a field of research in which he could distinguish himself. Chemists had long recognized that burning, like breathing, required air, and they also knew that iron rusts only upon exposure to air. Noting that burning gives off light and heat, that warm- blooded animals breathe, and that ores are turned into metals in a furnace, they concluded that fire was the key causal element behind these chemical reactions. The Enlightenment German chemist Georg Ernst Stahl pro- vided a well-regarded explanation of these phenomena. Stahl hypothesized that a common “fiery substance” he called phlogiston was released during combustion, respi- ration, and calcination, and that it was absorbed when these processes were reversed. Although plausible, this theory raised a number of problems for those who wished to explain chemical reactions in terms of substances that could be isolated and measured.
In the early stages of his research Lavoisier regarded the phlogiston theory as a useful hypothesis, but he sought ways either to solidify its firm experimental foundation or to replace it with an experimentally sound theory of com- bustion. In the end his theory of oxygenation replaced the phlogiston hypothesis, but it took Lavoisier many years and considerable help from others to reach this goal.

Oxygen Theory of Combustion
The oxygen theory of combustion resulted from a demanding and sustained campaign to construct an experimentally grounded chemical theory of combustion, respiration, and calcination. Lavoisier’s research in the early 1770s focused upon weight gains and losses in calcination. It was known that when metals slowly changed into powders (calxes), as was observed in the rusting of iron, the calx actually weighed more than the original metal, whereas when the calx was “reduced” to a metal, a loss of weight occurred. The phlogiston theory did not account for these weight changes, for fire itself could not be isolated and weighed. Lavoisier hypothesized that it was probably the fixation and release of air, rather than fire, that caused the observed gains and losses in weight. This idea set the course of his research for the next decade.
Along the way, he encountered related phenomena that had to be explained. Mineral acids, for instance, were made by roasting a mineral such as sulfur in fire and then mixing the resultant calx with water. Lavoisier had initially conjectured that the sulfur combined with air in the fire and that the air was the cause of acidity. However, it was not at all obvious just what kind of air made sulfur acidic. The problem was further complicated by the concurrent discovery of new kinds of airs within the atmosphere. British pneumatic chemists made most of these discoveries, with Joseph Priestley leading the effort.
And it was Priestley, despite his unrelenting adherence to the phlogiston theory, who ultimately helped Lavoisier unravel the mystery of oxygen. Priestley isolated oxygen in August 1774 after recognizing several properties that distinguished it from atmospheric air. In Paris at the same time, Lavoisier and his colleagues were experimenting with a set of reactions identical to those that Priestley was studying, but they failed to notice the novel properties of the air they collected. Priestley visited Paris later that year and at a dinner held in his honour at the Academy of Sciences informed his French colleagues about the properties of this new air. Lavoisier, who was familiar with Priestley’s research and held him in high regard, hurried back to his laboratory, repeated the experiment, and found that it produced precisely the kind of air he needed to complete his theory. He called the gas that was produced oxygen, the generator of acids. Isolating oxygen allowed him to explain both the quantitative and qualitative changes that occurred in combustion, respiration, and calcination.

The Chemical Revolution
In the canonical history of chemistry Lavoisier is celebrated as the leader of the 18th-century chemical revolution and consequently one of the founders of modern chemistry. Lavoisier was fortunate in having made his contributions to the chemical revolution before the disruptions of political revolution. By 1785 his new theory of combustion was gaining support, and the campaign to reconstruct chemistry according to its precepts began. One tactic to enhance the wide acceptance of his new theory was to propose a related method of naming chemical substances.
In 1787 Lavoisier and three prominent colleagues published a new nomenclature of chemistry, and it was soon widely accepted, thanks largely to Lavoisier’s eminence and the cultural authority of Paris and the Academy of Sciences. Its fundamentals remain the method of chemical nomenclature in use today. Two years later Lavoisier published a programmatic Traité élémentaire de chimie (Elementary Treatise on Chemistry) that described the pre- cise methods chemists should employ when investigating, organizing, and explaining their subjects. It was a worthy culmination of a determined and largely successful program to reinvent chemistry as a modern science.

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皮埃尔-西蒙·拉普拉斯侯爵（法語：Pierre-Simon marquis de Laplace，1749年3月23日－1827年3月5日），法国著名的天文学家和数学家，他的工作对天体力学和统计学有举足轻重的发展。(zh.wikipedia.org/皮埃尔-西蒙·拉普拉斯)

Pierre-Simon, marquis de Laplace was a French mathematician, astronomer, and physicist and is best known for his investigations into the stability of the solar system. Laplace successfully accounted for all the observed deviations of the planets from their theoretical orbits by applying Sir Isaac Newton’s theory of gravitation to the solar system, and he developed a conceptual view of evolu- tionary change in the structure of the solar system. He also demonstrated the usefulness of probability for interpreting scientific data.
Laplace was the son of a peasant farmer. Little is known of his early life except that he quickly showed his mathematical ability at the military academy at Beaumont. In 1766 Laplace entered the University of Caen, but he left for Paris the next year, apparently without taking a degree. He arrived with a letter of recommendation to the mathematician Jean d’Alembert, who helped him secure a professorship at the école Militaire, where he taught from 1769 to 1776.
In 1773 he began his major lifework—applying Newtonian gravitation to the entire solar system—by taking up a particularly troublesome problem: why Jupiter’s orbit appeared to be continuously shrinking while Saturn’s continually expanded. The mutual gravitational interactions within the solar system were so complex that mathematical solution seemed impossible; indeed, Newton had concluded that divine intervention was periodically required to preserve the system in equilibrium. Laplace announced the invariability of planetary mean motions (average angular velocity). This discovery in 1773, the first and most important step in establishing the stability of the solar system, was the most important advance in physical astronomy since Newton. It won him associate membership in the French Academy of Sciences the same year.
Applying quantitative methods to a comparison of liv- ing and nonliving systems, Laplace and the chemist Antoine-Laurent Lavoisier in 1780, with the aid of an ice calorimeter that they had invented, showed respiration to be a form of combustion. Returning to his astronomical investigations with an examination of the entire subject of planetary perturbations—mutual gravitational effects— Laplace in 1786 proved that the eccentricities and inclinations of planetary orbits to each other will always remain small, constant, and self-correcting. The effects of perturbations were therefore conservative and periodic, not cumulative and disruptive.
During 1784–85 Laplace worked on the subject of attraction between spheroids; in this work the potential function of later physics can be recognized for the first time. Laplace explored the problem of the attraction of any spheroid upon a particle situated outside or upon its surface. Through his discovery that the attractive force of a mass upon a particle, regardless of direction, can be obtained directly by differentiating a single function, Laplace laid the mathematical foundation for the scien- tific study of heat, magnetism, and electricity.
Laplace removed the last apparent anomaly from the theoretical description of the solar system in 1787 with the announcement that lunar acceleration depends on the eccentricity of the Earth’s orbit. Although the mean motion of the Moon around the Earth depends mainly on the gravitational attraction between them, it is slightly diminished by the pull of the Sun on the Moon. This solar action depends, however, on changes in the eccentricity of the Earth’s orbit resulting from perturbations by the other planets. As a result, the Moon’s mean motion is accelerated as long as the Earth’s orbit tends to become more circular; but, when the reverse occurs, this motion is retarded. The inequality is therefore not truly cumulative, Laplace concluded, but is of a period running into millions of years. The last threat of instability thus disappeared from the theoretical description of the solar system.
In 1796 Laplace published Exposition du système du monde (The System of the World), a semipopular treatment of his work in celestial mechanics and a model of French prose. The book included his “nebular hypothesis”—attributing the origin of the solar system to cooling and contracting of a gaseous nebula—which strongly influenced future thought on planetary origin. His Traité de mécanique céleste (Celestial Mechanics), appearing in five volumes between 1798 and 1827, summarized the results obtained by his mathematical development and application of the law of gravitation. He offered a complete mechanical interpretation of the solar system by devising methods for calculating the motions of the planets and their satellites and their perturbations, including the resolution of tidal problems. The book made him a celebrity.
In 1814 Laplace published a popular work for the general reader, Essai philosophique sur les probabilités (A Philosophical Essay on Probability). This work was the introduction to the second edition of his comprehensive and important Théorie analytique des probabilités (Analytic Theory of Probability), first published in 1812, in which he described many of the tools he invented for mathematically predicting the probabilities that particular events will occur in nature. He applied his theory not only to the ordinary problems of chance but also to the inquiry into the causes of phenomena, vital statistics, and future events, while emphasizing its importance for physics and astronomy. The book is notable also for including a special case of what became known as the central limit theorem. Laplace proved that the distribution of errors in large data samples from astronomical observations can be approximated by a Gaussian or normal distribution.
Probably because he did not hold strong political views and was not a member of the aristocracy, he escaped imprisonment and execution during the French Revolution. Laplace was president of the Board of Longitude, aided in the organization of the metric system, helped found the scientific Society of Arcueil, and was created a marquis. He served for six weeks as minister of the interior under Napoleon, who famously reminisced that Laplace “carried the spirit of the infinitesimal into administration.”

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愛德華·詹納（英文：Edward Jenner，1749年5月17日－1823年1月26日），FRS，亦譯作愛德華·金納或琴納，是一名英國醫生，生於英國告羅士打郡伯克利牧區一個牧師家庭，以研究及推廣牛痘疫苗，防止天花而聞名，被稱為疫苗之父。并且为后人的研究打开了通道，促使巴斯德、科赫等人针对其他疾病寻求治疗和免疫的方法。(zh.wikipedia.org/愛德華·詹納)

这枚PHQ不是英国皇家邮政极限明信片，因为它是把邮票放大印为明信片，包括齿孔，皇冠和面值。由于他们的存在，英国很少人用非PHQ片来自制极限明信片。PHQ 不能参加极限邮展，也许作为明信片类别展出。谁有极限明信片？

The 'PHQ' stands for Postal Headquarters. All items published by the Post Office are given a number which is prefixed by letters. The first card issued, on 16 May 1973, was numbered PHQ1, and the numbering sequence has continued to the present day.
There are three main areas of collecting interest. Many collectors like to collect only the unused cards, but some like to obtain them with first day of issue postmarks. Others like to obtain them with special handstamps that have some connection to the stamp subject matter. Also, stamp collectors will usually put the stamp on the back of the card, but a very popular variation is for the stamp to be applied to the face of the card, so that the postcard picture, stamp and postmark are all visible on the same face. (en.wikipedia.org/PHQ card)

22 02 2022 伦敦世展戳 在 五十三樓。

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English surgeon Edward Jenner is best known as the discoverer of vaccination for smallpox. Jenner lived at a time when the patterns of British medical practice and education were undergoing gradual change. During this time, the division between the trained physicians and the apothecaries or surgeons—who acquired their medical knowledge through apprenticeship rather than through academic work—was becoming less sharp, and hospital work was becoming much more important.
Jenner attended grammar school and at the age of 13 was apprenticed to a nearby surgeon. In the following eight years Jenner acquired a sound knowledge of medical and surgical practice. On completing his apprenticeship at the age of 21, he went to London and became the house pupil of John Hunter, who was on the staff of St. George’s Hospital and was one of the most prominent surgeons in London. Even more important, however, he was an anatomist, biologist, and experimentalist of the first rank; not only did he collect biological specimens, but he also concerned himself with problems of physiology and function.
The firm friendship that grew between the two men lasted until Hunter’s death in 1793. From no one else could Jenner have received the stimuli that so confirmed his natural bent—a catholic interest in biological phenomena, disciplined powers of observation, sharpening of critical faculties, and a reliance on experimental investigation. From Hunter, Jenner received the characteristic advice, “Why think [i.e., speculate]—why not try the experiment?”
In addition to his training and experience in biology, Jenner made progress in clinical surgery. After studying in London from 1770 to 1773, he returned to country practice in Berkeley and enjoyed substantial success. He was capable, skillful, and popular. In addition to practicing medicine, he joined two medical groups for the promotion of medical knowledge and wrote occasional medical papers. He played the violin in a musical club, wrote light verse, and, as a naturalist, made many observations, particularly on the nesting habits of the cuckoo and on bird migration. He also collected specimens for Hunter; many of Hunter’s letters to Jenner have been preserved, but Jenner’s letters to Hunter have unfortunately been lost. After one disappointment in love in 1778, Jenner married in 1788.
Smallpox was widespread in the 18th century, and occasional outbreaks of special intensity resulted in a very high death rate. The disease, a leading cause of death at the time, respected no social class, and disfigurement was not uncommon in patients who recovered. The only means of combating smallpox was a primitive form of vaccination called variolation—intentionally infecting a healthy person with the “matter” taken from a patient sick with a mild attack of the disease. The practice, which originated in China and India, was based on two distinct concepts: first, that one attack of smallpox effectively protected against any subsequent attack and, second, that a person deliberately infected with a mild case of the disease would safely acquire such protection. It was, in present-day terminology, an “elective” infection—i.e., one given to a person in good health. Unfortunately, the transmitted disease did not always remain mild, and mortality sometimes occurred. Furthermore, the inoculated person could disseminate the disease to others and thus act as a focus of infection.
Jenner had been impressed by the fact that a person who had suffered an attack of cowpox—a relatively harmless disease that could be contracted from cattle—could not take the smallpox—i.e., could not become infected whether by accidental or intentional exposure to small- pox. Pondering this phenomenon, Jenner concluded that cowpox not only protected against smallpox but could be transmitted from one person to another as a deliberate mechanism of protection.
The story of the great breakthrough is well known. In May 1796 Jenner found a young dairymaid, Sarah Nelmes, who had fresh cowpox lesions on her hand. On May 14, using matter from Sarah’s lesions, he inoculated an eight- year-old boy, James Phipps, who had never had smallpox. Phipps became slightly ill over the course of the next 9 days but was well on the 10th. On July 1 Jenner inoculated the boy again, this time with smallpox matter. No disease developed; protection was complete. In 1798 Jenner, having added further cases, published privately a slender book entitled An Inquiry into the Causes and Effects of the Variolae Vaccinae.The procedure spread rapidly to America and the rest of Europe and soon was carried around the world.
Despite errors and occasional chicanery, the death rate from smallpox plunged. Jenner received worldwide recognition and many honours, but he made no attempt to enrich himself through his discovery and actually devoted so much time to the cause of vaccination that his private practice and personal affairs suffered severely. Parliament voted him a sum of ￡10,000 in 1802 and a further sum of ￡20,000 in 1806. Jenner not only received honours but also aroused opposition and found himself subjected to attacks and calumnies, despite which he continued his activities on behalf of vaccination. His wife, ill with tuberculosis, died in 1815, and Jenner retired from public life.

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这枚是英国剑桥大学教授印制品。

22 02 2022 伦敦世展戳 在 五十三樓。

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约翰·道尔顿（英語：John Dalton，/ˈdɔːltən/，1766年9月6日－1844年7月27日），英国皇家学会成员，化学家、物理学家。近代原子理论的提出者，对色盲亦有研究。很多化学家使用道尔顿作为原子量的单位。(zh.wikipedia.org/约翰·道尔顿).

English meteorologist and chemist John Dalton was a pioneer in the development of modern atomic theory.

Early Scientific Career
In 1793 Dalton published a collection of essays, Meteorological Observations and Essays, on meteorologic topics based on his own observations together with those of his friends John Gough and Peter Crosthwaite. It created little stir at first but contained original ideas that, together with Dalton’s more developed articles, marked the transition of meteorology from a topic of general folklore to a serious scientific pursuit.
Dalton upheld the view, against contemporary opinion, that the atmosphere was a physical mixture of approximately 80 percent nitrogen and 20 percent oxygen rather than being a specific compound of elements. He measured the capacity of the air to absorb water vapour and the variation of its partial pressure with temperature. He defined partial pressure in terms of a physical law whereby every constituent in a mixture of gases exerted the same pressure it would have if it had been the only gas present. One of Dalton’s contemporaries, the British scientist John Frederic Daniell, later hailed him as the “father of meteorology.”
Soon after the publication of the essays, Dalton wrote a description of the defect he had discovered in his own and his brother’s vision. This paper was the first publication on colour blindness, which for some time thereafter was known as Daltonism.

Atomic Theory
By far Dalton’s most influential work in chemistry was his atomic theory. Attempts to trace precisely how Dalton developed this theory have proved futile; even Dalton’s own recollections on the subject are incomplete. He based his theory of partial pressures on the idea that only like atoms in a mixture of gases repel one another, whereas unlike atoms appear to react indifferently toward each other. This conceptualization explained why each gas in a mixture behaved independently. Although this view was later shown to be erroneous, it served a useful purpose in allowing him to abolish the idea, held by many previous atomists from the Greek philosopher Democritus to the 18th-century mathematician and astronomer Ruggero Giuseppe Boscovich, that atoms of all kinds of matter are alike. Dalton claimed that atoms of different elements vary in size and mass, and indeed this claim is the cardinal feature of his atomic theory. He focused upon determining the relative masses of each different kind of atom, a process that could be accomplished, he claimed, only by considering the number of atoms of each element present in different chemical compounds.
Although Dalton had taught chemistry for several years, he had not yet performed actual research in this field. In a memoir read to the Manchester Literary and Philosophical Society on Oct. 21, 1803, he claimed: “An inquiry into the relative weights of the ultimate particles of bodies is a subject, as far as I know, entirely new; I have lately been prosecuting this inquiry with remarkable success.” He described his method of measuring the masses of various elements, including hydrogen, oxygen, carbon, and nitrogen, according to the way they combined with fixed masses of each other. If such measurements were to be meaningful, the elements had to combine in fixed pro- portions. His measurements, crude as they were, allowed him to formulate the Law of Multiple Proportions: When two elements form more than one compound, the masses of one element that combine with a fixed mass of the other are in a ratio of small whole numbers. Thus, taking the ele- ments as A and B, various combinations between them naturally occur according to the mass ratios A:B = x:y or x:2y or 2x:y, and so on. Different compounds were formed by combining atomic building blocks of different masses. As the Swedish chemist Jöns Jacob Berzelius wrote to Dalton: “The law of multiple proportions is a mystery without the atomic theory.” And Dalton provided the basis for this theory.
The problem remained, however, that a knowledge of ratios was insufficient to determine the actual number of elemental atoms in each compound. For example, meth- ane was found to contain twice as much hydrogen as ethylene. Following Dalton’s rule of “greatest simplicity,” namely, that AB is the most likely combination for which he found a meretricious justification in the geometry of close-packed spheres, he assigned methane a combination of one carbon and two hydrogen atoms and ethylene a combination of one carbon and one hydrogen atom. This is now known to be incorrect because the methane mole- cule is chemically symbolized as CH4 and the ethylene molecule as C2H4. Nevertheless, Dalton’s atomic theory triumphed over its weaknesses because his foundational argument was correct. However, overcoming the defects of Dalton’s theory was a gradual process, finalized in 1858 only after the Italian chemist Stanislao Cannizzaro pointed out the utility of Amedeo Avogadro’s hypothesis in deter- mining molecular masses. Since then, chemists have shown
the theory of Daltonian atomism to be a key factor underlying further advances in their field. Organic chemistry in particular progressed rapidly once Dalton’s theory gained acceptance. Dalton’s atomic theory earned him the sobriquet “father of chemistry.”


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喬治·利奧波德·克雷蒂安·弗列德里克·達戈貝爾·居維葉男爵（法語：Baron Georges Léopold Chrétien Frédéric Dagobert Cuvier；1769年8月23日－1832年5月13日），簡稱喬治·居維葉（Georges Cuvier），法國博物學家、比较解剖学家與動物學家，也被称为“古生物学之父”。為博物學家弗列德利克·居維葉之兄，为19世紀早期的巴黎科學界名人之一。他在动物和化石方面的研究开启了比较解剖学和古生物学领域。

维叶的研究被认为是脊椎动物古生物学的基础，他扩展了卡尔·林奈分类法，将门分入不同的纲，并将化石和动物纳入分类系统。居维叶是最早确认了生物灭绝的生物学家。在他1813年的《对地球理论的论文》（Theory of the Earth）中，提出新的物种在周期性的灾难性的洪水后产生。他是19世纪初灾变论学说最具影响力的支持者。他与亚历山大·布隆尼亚尔对巴黎盆地地层的研究确立了生物地层学的基本原则。他的其他成就包括，确认了在美国发现的类似大象的骨头属于一种灭绝的动物，并将其命名为乳齿象；在巴拉圭挖掘的大骨骼是大地懒，一种巨大的史前地面树懒；命名了翼龙；描述了水生爬行动物沧龙。并且他第一个提出史前地球由爬行动物（而非哺乳动物）占据主导地位。(zh.wikipedia.org/喬治·居維葉)

French zoologist and statesman Baron Georges Cuvier established the sciences of comparative anatomy and paleontology. From 1784 to 1788 Cuvier attended the Académie Caroline (Karlsschule) in Stuttgart, Ger., where he studied comparative anatomy and learned to dissect. After graduation Cuvier served in 1788–95 as a tutor, during which time he wrote original studies of marine invertebrates, particularly the mollusks. His notes were sent to étienne Geoffroy Saint-Hilaire, a professor of zoology at the Museum of Natural History in Paris, and at Geoffroy’s urging Cuvier joined the staff of the museum. For a time the two scientists collaborated, and in 1795 they jointly published a study of mammalian classification, but their views eventually diverged.

Cuvier remained at the museum and continued his research in comparative anatomy. His first result, in 1797, was Tableau élémentaire de l’histoire naturelle des animaux (“Elementary Survey of the Natural History of Animals”), a popular work based on his lectures. In 1800–05, he published his Leçons d’anatomie comparée (“Lessons on Comparative Anatomy”). In this work, based also on his lectures at the museum, he put forward his principle of the “correlation of parts,” according to which the anatomical structure of every organ is functionally related to all other organs in the body of an animal, and the functional and structural characteristics of organs result from their interaction with their environment. Moreover, according to Cuvier, the functions and habits of an animal determine its anatomical form, in contrast to Geoffroy, who held the reverse theory—that anatomical structure preceded and made necessary a particular mode of life.

Cuvier also argued that the anatomical characteristics distinguishing groups of animals are evidence that species had not changed since the Creation. Each species is so well coordinated, functionally and structurally, that it could not survive significant change. He further maintained that each species was created for its own special purpose and each organ for its special function. In denying evolution, Cuvier disagreed with the views of his colleague Jean-Baptiste Lamarck, who published his theory of evolution in 1809, and eventually also with Geoffroy, who in 1825 published evidence concerning the evolution of crocodiles.

While continuing his zoological work at the museum, Cuvier served as imperial inspector of public instruction and assisted in the establishment of French provincial universities. For these services he was granted the title “chevalier” in 1811. He also wrote the Rapport historique sur les progrès des sciences naturelles depuis 1789, et sur leur état actuel (“Historical Report on the Progress of the Sciences”), published in 1810. These publications are lucid expositions of the European science of his time.

Meanwhile, Cuvier also applied his views on the correlation of parts to a systematic study of fossils that he had excavated. He reconstructed complete skeletons of unknown fossil quadrupeds. These constituted astonishing new evidence that whole species of animals had become extinct. Furthermore, he discerned a remarkable sequence in the creatures he exhumed. The deeper, more remote strata contained animal remains—giant salamanders, flying reptiles, and extinct elephants—that were far less similar to animals now living than those found in the more recent strata. He summarized his conclusions, first in 1812 in his Recherches sur les ossements fossiles de quadrupèdes (“Researches on the Bones of Fossil Vertebrates”), which included the essay “Discours préliminaire” (“Preliminary Discourse”), as well as in the expansion of this essay in book form in 1825, Discours sur les révolutions de la surface du globe (“Discourse on the Revolutions of the Globe”).

Cuvier’s work gave new prestige to the old concept of catastrophism according to which a series of “revolutions,” or catastrophes—sudden land upheavals and floods—had destroyed entire species of organisms and carved out the present features of the Earth. He believed that the area laid waste by these spectacular paroxysms, of which Noah’s flood was the most recent and dramatic, was sometimes repopulated by migration of animals from an area that had been spared. Catastrophism remained a major geologic doctrine until it was shown that slow changes over long periods of time could explain the features of the Earth.

In 1817 Cuvier published Le Règne animal distribué d ’après son organisation (“The Animal Kingdom, Distributed According to Its Organization”), which, with its many subsequent editions, was a significant advance over the systems of classification established by Linnaeus. Cuvier showed that animals possessed so many diverse anatomical traits that they could not be arranged in a single linear system. Instead, he arranged animals into four large groups of animals (vertebrates, mollusks, articulates, and radiates), each of which had a special type of anatomical organization. All animals within the same group were classified together, as he believed they were all modifications of one particular anatomical type. Although his classification is no longer used, Cuvier broke away from the 18th-century idea that all living things were arranged in a continuous series from the simplest up to man.

Cuvier’s lifework may be considered as marking a transition between the 18th-century view of nature and the view that emerged in the last half of the 19th century as a result of the doctrine of evolution. By rejecting the 18th- century method of arranging animals in a continuous series in favour of classifying them in four separate groups, he raised the key question of why animals were anatomically different. Although Cuvier’s doctrine of catastrophism did not last, he did set the science of palaeontology on a firm, empirical foundation. He did this by introducing fossils into zoological classification, showing the progressive relation between rock strata and their fossil remains, and by demonstrating, in his comparative anatomy and his reconstructions of fossil skeletons, the importance of functional and anatomical relationships.

全文可在 www.arvindguptatoys.com/arvindgupta/hundred-scientists.pdf 下载。

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弗里德里希·威廉·海因里希·亚历山大·冯·洪堡（德语：Friedrich Wilhelm Heinrich Alexander von Humboldt，1769年9月14日－1859年5月6日），德国自然科学家、自然地理学家，近代气候学、植物地理学、地球物理学的创始人之一；涉猎科目很广，特别是生物学与地质学。教育家、柏林大學創始人威廉·馮·洪堡是其兄。他被誉为现代地理学的金字塔和现代地理学之父。还是英国皇家学会外籍会员。

晚年所写的5卷《宇宙》（德語：Kosmos，原著用法文写成）是他描述地球自然地理的著作。其对地理学和生物学有巨大贡献。如他认为自然界为一巨大的整体，各种自然现象相互联系，并依其内部力量不断运动发展；亦常从直接观察的事实出发，运用比较法，揭示自然现象之间的因果关系。同时，他开创了许多地理学界的重要概念，如等温线、等压线、地形剖面图、海拔温度梯度、洋流、植被的水平与垂直分布、气候带分布、温度垂直递减率、大陆东西岸温度差异、大陆性与海洋气候、地形对气候形成的作用等，并探讨气候同动植物的水平分异和垂直分异的关系；此外，他也发现地磁强度从极地向赤道递减的规律，火山分布与地下裂隙的关系等。(zh.wikipedia.org/亚历山大·冯·洪堡)

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German naturalist and explorer Alexander von Humboldt was a major figure in the classical period of physical geography and biogeography—areas of science now included in the earth sciences and ecology. With his book Kosmos he made a valuable contribution to the popularization of science. The Humboldt Current off the west coast of South America was named after him.

Expedition to South America
The conviction had grown in Humboldt that his real aim in life was scientific exploration, and in 1797 he set himself to acquiring a thorough knowledge of the systems of geodetic, meteorological, and geomagnetic measurements. He obtained permission from the Spanish government to visit the Spanish colonies in Central and South America. Completely shut off from the outside world, these colonies offered enormous possibilities to a scientific explorer. Humboldt’s social standing assured him of access to official circles, and in the Spanish prime minister Mariano de Urquijo he found an enlightened man who supported his application to the king for a royal permit. In the summer of 1799 he set sail from Marseille accompanied by the French botanist Aimé Bonpland, whom he had met in Paris, then the liveliest scientific centre in Europe. The estate he had inherited at the death of his mother enabled Humboldt to finance the expedition entirely out of his own pocket. Humboldt and Bonpland spent five years, from 1799 to 1804, in Central and South America, covering more than 6,000 miles (9,650 kilometres) on foot, on horseback, and in canoes. It was a life of great physical exertion and serious deprivation.

Starting from Caracas, they travelled south through grasslands and scrublands until they reached the banks of the Apure, a tributary of the Orinoco River. They continued their journey on the river by canoe as far as the Orinoco. Following its course and that of the Casiquiare, they proved that the Casiquiare River formed a connection between the vast river systems of the Amazon and the Orinoco. For three months Humboldt and Bonpland moved through dense tropical forests, tormented by clouds of mosquitoes and stifled by the humid heat. Their provisions were soon destroyed by insects and rain; the lack of food finally drove them to subsist on ground-up wild cacao beans and river water.

After a short stay in Cuba, Humboldt and Bonpland returned to South America for an extensive exploration of the Andes. From Bogotá to Trujillo, Peru, they wandered over the Andean Highlands—following a route now traversed by the Pan-American Highway, in their time a series of steep, rocky, and often very narrow paths. They climbed a number of peaks, including all the volcanoes in the sur- roundings of Quito, Ecuador; Humboldt’s ascent of Chimborazo (20,702 feet [6,310 metres]) to a height of 19,286 feet (5,878 metres), but short of the summit, remained a world mountain-climbing record for nearly 30 years. All these achievements were carried out without the help of modern mountaineering equipment, without ropes, crampons, or oxygen supplies; hence, Humboldt and Bonpland suffered badly from mountain sickness. But Humboldt turned his discomfort to advantage: he became the first person to ascribe mountain sickness to lack of oxygen in the rarefied air of great heights. He also studied the oceanic current off the west coast of South America that was originally named after him but is now known as the Peru Current.

In the spring of 1803, the two travellers sailed from Guayaquil to Acapulco, Mex., where they spent the last year of their expedition in a close study of this most developed and highly civilized part of the Spanish colonies. After a short stay in the United States, where Humboldt was received by President Jefferson, they sailed for France. Humboldt and Bonpland returned with an immense amount of information. In addition to a vast collection of new plants, there were determinations of longitudes and latitudes, measurements of the components of the Earth’s geomagnetic field, and daily observations of temperatures and barometric pressure, as well as statistical data on the social and economic conditions of Mexico.

Professional Life in Paris
The years from 1804 to 1827 Humboldt devoted to publi- cation of the data accumulated on the South American expedition. With the exception of brief visits to Berlin, he lived in Paris during this important period of his life. There he found not only collaborators among the French scientists—the greatest of his time—but engravers for his maps and illustrations and publishers for printing the 30 volumes into which the scientific results of the expedition were distilled. Of great importance were the meteorologi- cal data, with an emphasis on mean daily and nightly temperatures, and Humboldt’s representation on weather maps of isotherms (lines connecting points with the same mean temperature) and isobars (lines connecting points with the same barometric pressure for a given time or period)—all of which helped lay the foundation for the science of comparative climatology.

Even more important were his pioneering studies on the relationship between a region’s geography and its flora and fauna, and, above all, the conclusions he drew from his study of the Andean volcanoes concerning the role played by eruptive forces and metamorphosis in the history and ongoing development of the Earth’s crust. Lastly, his Political Essay on the Kingdom of New Spain contained a wealth of material on the geography and geology of Mexico, including descriptions of its political, social, and economic conditions, and also extensive population statistics.

During his years in Paris, Humboldt had the ability to cultivate deep and long-lasting friendships with well- known scientists, such as the renowned physicist and astronomer François Arago, and to evoke respect and admiration from the common man, an ability that reflected his generosity, humanity, and vision of what science could do. He was, moreover, always willing and anxious to assist young scientists at the beginning of their careers. Such men as the German chemist Justus von Liebig and the Swiss-born zoologist Louis Agassiz owed to Humboldt the means to continue their studies and embark on an aca career. The best proof of his wide interests and affectionate nature lies in his voluminous correspondence: about 8,000 letters remain.

Later Years
In 1827 Humboldt had to return to Berlin, where the King impatiently demanded his presence at court. In 1829 Humboldt was given the opportunity to visit Russia and Siberia. On the initiative of the Russian minister of finance, Count Yegor Kankrin, he was invited to visit the gold and platinum mines in the Urals. This expedition, lasting only one summer, was very different from the South American journey; the members, Humboldt and two young scien- tists, were accompanied throughout by an official guard, since they were guests of the Tsar. Humboldt and his companions had to endure tiresome receptions at the imperial court and in the homes of provincial governors. They travelled in carriages as far as the Altai Mountains and the Chinese frontier. The resulting geographical, geological, and meteorological observations, especially those regarding the Central Asian regions, were of great importance to the Western world, for Central Asia was then to a large degree unknown territory.

Even before his visit to Russia, he had returned to an investigation of a phenomenon that had aroused his interest in South America: the sudden fluctuations of the Earth’s geomagnetic field—the so-called magnetic storms. With the help of assistants, he carried out observations of the movement of a magnetometer in a quiet garden pavilion in Berlin; but it had been clear to him for a number of years that, to discover whether these magnetic storms were of terrestrial or extraterrestrial origin, it would be necessary to set up a worldwide net of magnetic observatories. The German mathematician Carl Friedrich Gauss had already begun to organize simultaneous measurements of the magnetic field by several observatories in Germany, England, and Sweden.

In 1836 Humboldt, still interested in the problem, approached the Royal Society in London with the request that it establish an additional series of stations in the British possessions overseas. As a result, the British government provided the means for permanent observatories in Canada, South Africa, Australia, and New Zealand and equipped an Antarctic expedition. With the help of the mass of data produced by this international scientific collaboration, one of the first of its kind, the English geophysicist Sir Edward Sabine later succeeded in correlating the appearance of magnetic storms in the Earth’s atmosphere with the periodically changing activity of sunspots, thus proving the extraterrestrial origin of the storms.

During the last 25 years of his life, Humboldt was chiefly occupied with writing Kosmos, one of the most ambitious scientific works ever published. Four volumes appeared during his lifetime. Written in a pleasant, literary style, Kosmos gives a generally comprehensible account of the structure of the universe as then known, at the same time communicating the scientist’s excitement and aesthetic enjoyment at his discoveries. Humboldt had taken immense pains to discipline his inclination to discursive- ness, which often gave his writing a certain lack of logical coherence. He was rewarded for his effort by the success of his book, which, within a few years, had been translated into nearly all European languages.

全文可在 www.arvindguptatoys.com/arvindgupta/hundred-scientists.pdf 下载。

这枚德国邮票纪念 弗里德里希·威廉·海因里希·亚历山大·冯·洪堡 诞生250年今年9月发行。

ngsunyu

纪念名人而发行的邮票是司空见惯的，例如 皇族，政治家，将军，艺术家，音乐家和科学家。这些邮票已经被制成了许多极限明信片。一个例子是为纪念皇家学会的著名成员而发行的2010年皇家邮政邮票。现有所有的极限明信片都是自制的，包括我的牛顿极限明信片（请参阅第30和31层）以及剑桥大学植物学教授自制的其他几枚（请参阅第25和40层以及未来的内容）。

我在将近五个月前开始写这个主题，研究科学家极限明信片的供求如何。由于中国的目标是成为本世纪及以后的科技大国，所以我也希望大众对科学家极限明信片有高度的兴趣。今年9月发行的这枚德国邮票纪念 弗里德里希·威廉·海因里希·亚历山大·冯·洪堡 诞生250年是今年的测试题。是否会有其他收集家(不一定是专业科学家)当他/她知道此邮票发行时，便会自制类似的极限明信片吗？等待结果中。