A Short History of Science – Part II
By Tim Lambert
Science in the 18th Century
During the 18th century chemistry made great advances. In 1766 a man named Henry Cavendish (1731-1810) isolated hydrogen and studied its properties. (He also calculated the density of the Earth). In 1772 Daniel Rutherford (1749-1819) discovered nitrogen. Two men, Joseph Priestly (1733-1804) and Karl Scheele (1742-1786) discovered oxygen. In 1756 Joseph Black (1728-1799) discovered carbon dioxide.
Perhaps the greatest chemist of the 18th century was Antoine Lavoisier (1743-1794). He discovered that during combustion oxygen combines with substances. He also discovered the role of oxygen in respiration and corrosion of metals.
Meanwhile during the 18th century people began to realized that the Earth is very old. A landmark in geology came in 1785 when James Hutton (1726-1797) published his book 'Theory of the Earth'.
Two great biologists of the 18th century were Georges Leclerc, Comte de Buffon (1707-1788) and Karl Linnaeus (1707-1778). Linnaeus invented a method of classifying living things.
Meanwhile people began to investigate electricity. In 1746 a man Petrus van Musschenbroek (1692-1761) invented a way of storing electricity called a leiden jar. In 1752 Benjamin Franklin (1706-1790) proved that lighting is a form of electricity.
Then in 1800 Alessandro Volta (1745-1827) invented the first chemical battery.
However during the 18th century medicine made slow progress. Doctors still did not know what caused disease. Some continued to believe in the four humors (although this theory declined during the 18th century). Other doctors thought disease was caused by 'miasmas' (odorless gases in the air).
Science in the 19th Century
During the 19th century science made great progress. In 1803 John Dalton (1766-1844) published his atomic theory. According to the theory matter is made of tiny, indivisible particles. Dalton also said that atoms of different elements had different weight. John Dalton also studied colour blindness.
In 1827 the German chemist Friedrich Wohler (1800-1882) isolated aluminium. In 1828 he produced urea, an organic compound from inorganic chemicals.
A Russian, Dmitri Mendelev (1834-1907) formulated the Periodic Table, which arranged all the known elements according to their atomic weight.
Meanwhile men continued to master electricity. In 1819 a Dane, Hans Christian Oersted discovered that electric current in a wire caused a nearby compass needle to move.The Englishman Michael Faraday (1791-1867) invented the dynamo.
In 1847 the German Hermann von Helmholtz (1821-1894) formulated the law of the Conservation of Energy, which states that energy is never lost but just changes from one form to another. In 1851 he invented the ophthalmoscope.
Meanwhile geology made huge strides. Charles Lyell (1797-1875) saw that rocks were formed by processes we see today. In 1830 he published his book 'Principles of Geology'. In 1837 a Swiss, Louis Agassiz (1807-1873) realized that a vast sheet of ice had once covered northern Europe. Furthermore scientists discovered more and more fossils and the word Dinosaur was coined in 1842.
In 1831 Charles Darwin sailed on the Beagle. In February 1832 the Beagle reached Brazil. Darwin spent three years in different parts of South America collecting specimens. Then in September 1835 the Beagle sailed to the Galapagos Islands.
Darwin was surprised to learn the local people could tell by looking at a tortoise which island it came from. Darwin also studied finches. Each island had a different species of finch. Later Darwin came to the conclusion that all were descended from a single species of finch. On each island the finches had diverged and become slightly different.
By 1836 Darwin believed that species of animals could change. In October 1838 Darwin thought of a way in which one species could change into another. He noticed that individual members of a species vary. Furthermore all animals are competing with each other to survive. If the environment changed in some way, say if a new, faster predator appeared then any herbivores that could run slightly faster then other members of its species would be more likely to survive and reproduce. Any herbivores that ran slightly slower than most would be more likely to be eaten. Slowly a new, faster herbivore would evolve. This was later called the survival of the fittest.
Darwin's monumental work 'The Origin of Species' was published in 1859. It proved to be a bestseller. However Darwin's book also caused controversy.
In 1866 an Austrian monk named Gregor Mendel discovered the laws of hereditary by breeding peas.
Furthermore medicine and surgery made great advances in the 19th century.
During the 19th century there were several outbreaks of cholera in Britain. It struck in 1832, 1848, 1854 and 1866. During the 1854 epidemic John Snow (1813-1858) showed that cholera was transmitted by water. However doctors were not certain how.
Later Louis Pasteur (1822-1895) proved that microscopic organisms caused disease. In the early 19th century many scientists believed in spontaneous generation i.e. that some living things spontaneously grew from non-living matter. In a series of experiments between 1857 and 1863 Pasteur proved this was not so. Once doctors found what caused disease they made rapid headway in finding cures or prevention.
In the late 19th century physics made great strides. In 1873 James Clerk Maxwell (1831-1879) showed that light is an electromagnetic wave. He also predicted there were other electromagnetic waves with longer and shorter wavelengths than light.
Then in 1888 Heinrich Hertz (1857-1894) proved the electromagnetic waves predicted by Maxwell exist.
In 1896 Henri Becquerel (1852-1908) discovered radioactivity. Then in 1898 Marie Curie (1867-1934) and Pierre Curie (1859-1906) discovered radium.
Finally at the end of the century scientists began to investigate the atom. In 1897 Joseph Thomson discovered the electron.
In astronomy, Giuseppe Piazzi (1746-1826) discovered the first asteroid, Ceres in 1801. In 1838 Friedrich Bessel (1784-1846) measured the distance to a star (61 Cygni) for the first time. The planet Neptune was discovered in 1846.
Science in the 20th Century
During the 20th century science continued to go forward at fantastic speed.
During the 20th century scientists came to understand the atom. In 1910 Ernest Rutherford (1871-1937) discovered the atomic nucleus. He realized that almost all the mass of an atom is in the nucleus with electrons orbiting it.
Physics was revolutionized by two men, Max Planck (1858-1947) and Albert Einstein (1879-1955). In 1900 Planck proposed quantum theory, which states that energy is exchanged in discrete packets he called quanta. Einstein published his theory of Special Relativity in 1905 and his General Theory of Relativity in 1915.
In 1927 Werner Heisenberg (1901-1976) published his uncertainty principle, which states that is impossible to determine the position and speed of a subatomic particle.
In 1915 Alfred Wegener proposed continental drift. He said that all continents were once joined and they have drifted apart.
In 1926 Arthur Eddington (1882-1944) suggested that stars are powered by nuclear fusion. Also in the 1920s Edwin Hubble (1889-1953) showed that our galaxy is only one of many galaxies. He also proved that the universe is expanding. In 1930 Clyde Tombaugh discovered Pluto. The first radio telescope was built in 1937.
Meanwhile medicine was making great advances. In 1928 Alexander Fleming (1881-1955) discovered penicillin.
Meanwhile genetics was making great strides. In 1953 Francis Crick and James Watson discovered the double-helix structure of DNA. At the end of the 20th century genetic engineering became possible.
In astronomy quasars were discovered in 1963 and pulsars were discovered in 1968. The Hubble Space Telescope was launched in 1990. At the end of the 20th century the first extra solar planets were discovered. At the other end of the scale scientists discovered many new sub-atomic particles. In 1964 Murray Gell-Mann (1929-) suggested that quarks exist.
The most famous physicist of the late 20th century is Stephen Hawking (1942-). Hawking is known for his research into black holes, relativity and cosmology.
We would like to thank Tim Lambert, author of this article, for the permission to republish his article on our website. To see the original article and many more on history, please visit http://www.localhistories.org
A Short History of Science – Part II – Comprehension Questions
1. Which scientific discipline did not make great progress in the 18th century and why?
2. What was Darwin's great contribution to science?
3. Which discoveries were made in the worlds of the infinitely small and the world of infinitely large in the 20th century?