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Some Developments 1650 to the Present

Some Developments 1650 to the Present. From 1650 onwards the foundations were present for new discoveries It became recognised that science could make a contribution to everyday life:- To cure diseases & control public health To monitor the quality of drinking water To study fisheries.

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Some Developments 1650 to the Present

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  1. Some Developments 1650 to the Present

  2. From 1650 onwards the foundations were present for new discoveries It became recognised that science could make a contribution to everyday life:- • To cure diseases & control public health • To monitor the quality of drinking water • To study fisheries • Learned Societies • were formed: • England Royal Society • France Royal Academy of Sciences • USA Boston Philosophical Society

  3. For Biology the use of the MICROSCOPE was the big break-through: Crude lenses - from early Roman days Galileo invented microscope & telescope Use of microscope for study of biological science was introduced by:- In 1674 - he discovered blood corpuscles In 1683 - he discovered blood capillaries {the missing part of Harvey’s story} He also looked at cells, nuclei, molds, microbes, pollen grains house mites, cow’s optic, nerve, sperm cells His work was followed in 1737 by Swammerdam who examined lungs, lymphatic system & the spine (as well as insects). A van L and S showed that the microscope added much to classical biology. Botany was also revived with microscopy: 1670 - Nehemiah Grew wrote books on Anatomy of vegetables, plants, flowers & roots ANTONI VAN LEEUVENHOEK (1632-1723)

  4. Developments in microscopy Limitations were due to -Poor lenses -Chromatic abberation -The wavelength of light Joseph Jackson Lister 1786-1869 solved some of this with better lenses His son was Joseph Lister the surgeon who developed antiseptics Brewster – 1800 immersion microscopy + filters ---->monochromatic light Abbe & Zeiss- 1850-1900 new glass for lenses, fixing and staining methods Fritz Zernike - 1940s phase contrast microscopy • colourless biological material shown up by differences in refractive index. From 1930- Electon microscopes available

  5. Progression of Biological Sciences The Microscope changed the course of biology from purely anatomical to cellular

  6. C. Mid 18th to mid 20th Century This was also called the age of enlightenment- a basic belief of the superiority of reason over superstition The success of Newtonian physics in providing a mathematical description of an ordered world encouraged biochemists and chemists to think that the biological world might have similar basic laws James Watt, born in Greenock Jan 1736: first person to take results from research and apply them to technology- improvements in steam engine. He was in direct contact with researchers at university: basis for today’s high-tech industries with research laboratories

  7. Joseph Priestly (1733-1804)born in Leeds Discovered OXYGEN and other gases (NH3, SO2, CO, H2S) He noted that this new gas (O2) • Made candles burn more brightly • Extended survival time for mice in confined space • In sun, plants revive poor air (release O2) • Animals consumed good air (& gave CO2) Antoine-Laurent Lavoisier 1743 France took Priestly’s observations and explained respiration as a slow combustion that used O2 and released CO2. Published Traite Elementaire de Chimie in 1789 (same year as French revolution)- regarded in same league as Newton’s masterwork. Lavoisier was guillotined in 1794 THIS WAS THE START OF CHEMISTRY LINKED TO BIOLOGY

  8. John Dalton 1766English Introduced the idea of atoms and atomic weights, but it was only in the 20th century that existence of atoms was proven. Lothar Meyer1830 German Published the periodic table of elements (arranged in order of atomic weights) James Joule 1818 son of a wealthy English brewer Showed that work is converted into heat by stirring water with a paddle wheel and measuring rise in temperature. William Kelvin 1822 English Developed laws of thermodynamics Albert Enstein 1880 German Avagadro’s number (measurements of size of molecules); Brownian motion: Developed an equation that linked Avogadro’s number with the speed with which molecules move and the measurable rate at which molecules drift away. Early 1900’s-Nobel prize for relativity theory

  9. Josef von Fraunhofer 1787 German Lines in solar spectrum (Fraunhofer lines)- developed spectroscopy. Further developed by Robert Bunsen (1811-) –name of Bunsen burner in laboratory- key tool in development of spectroscopy! Michael Faraday 1791- electromagnetism, invention of electric motor and dynamo. Claude Bernard (1813-1878)France • Showed that the constant level of sugar in the blood was because of a store of glucose in the liver as a polymer of glucose - GLYCOGEN • Action of pancreatic juices on digestion • Function of the nerves Bernard showed that life processes were chemical not spiritual !

  10. Modern Period 1900’s - now Marie Curie 1870- radioactoivity Ernst Rutherford 1871- isotopes; radioactive decay Niels Bohr 1885- quantum model of the atom Erwin Schrődinger1878-wave equation • Book: What is life? anticipate work of Crick an Watson-classic Darwin in evolution -1859 Hermann Fol 1845- observed penetration of sperm into egg Walter Flemming 1843- duplication of chromosomes August Weisman 1833-cell division by chromosomes-reproduction-disprove Lamarckian theory Hugo de Vries 1848- pangens: characteristics of species made from a large number of distinct units, each of them due to a single hereditary factor, which is passed on from one generation to the next - origin of term ‘gene’ Gregor Mendel 1822- independently – laws of inheretance (published in 1865)

  11. Phoebus Levene 1869-American- founder of Rockefeler institute in New York in 1905: Played a leading part in identifying building blocks of RNA and identified DNA in 1929- identified G, A, C and U of nucleic acid- the tetranucleotide hypothesis. This single code of GACU was supposed to result in complex proteins- but it was too simplistic. Ostwald Avery 1877-showed a transformation agent that turned harmless pneumococci into fatal ones- evidence that DNA convey genetic information Watson, Crick and Wilkins 1962: Nobel prize for unravelling the genetic code and the structure of DNA

  12. The development of the concept of vitamins Scurvy - known for hundreds of years . Disease involves:- - rapid exhaustion - muscular pains - gums ulcerate & teeth drop out - lung and kidney troubles - eventual death 1497-98 Vasco da Gama Lisbon/Africa/India • 160 crew of which 100 died of scurvy On long sea voyages sailors lived on- Biscuits & salted beef (no vitamin C) In 1577 Spanish Galleon found adrift - everyone on board was dead The development of the idea that vitamin C prevented and cured scurvy took a long time and many hopeful pointers were ignored

  13. The route to a cure for scurvy • 1536 French explorer Jaques Cartier - discovered the St Lawrence River - sailed to Quebec - spent winter - 25 died of scurvy BUT:- - a local Indian told them to drink tea made from needles & bark of tree Treatment worked - but no one took much note. [Now we know that these leaves have vit C] • 1747 James Lind - Doctor, British Navy - expts: oranges, lemons and scurvy Excellent results BUT................ Further expts with boiled juices failed. • 1795 British Navy - lime juice in rations British referred to as Limeys

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