• JOHH SHOW DEFEATS “KING CHOLERA”
  • John Snow was a famous doctor in London - so expert,
  • indeed,
  • that he attended Queen Victoria as her personal physician.
  • But he became inspired when he thought about helping ordinary people exposed to cholera.
  • This was the deadly disease of its day.
  • Neither its cause nor its cure was understood.
  • So many thousands of terrified people died every time there was an outbreak.
  • John Snow wanted to face the challenge and solve this problem.
  • He knew that cholera would never be controlled until its cause was found.
  • He became interested in two theories that possibly explained how cholera killed people.
  • The first suggested that cholera multiplied in the air.
  • A cloud of dangerous gas floated around until it found its victims.
  • The second suggested that people absorbed this disease into their bodies with their meals.
  • From the stomach the disease quickly attacked the body and soon the affected person died.
  • John Snow suspected that the second theory was correct but he needed evidence.
  • So when another outbreak hit London in 1854,
  • he was ready to begin his enquiry.
  • As the disease spread quickly through poor neighbourhoods,
  • he began to gather information.
  • In two particular streets,
  • the cholera outbreak was so severe that more than 500 people died in ten days.
  • He was determined to find out why.
  • First he marked on a map the exact places where all the dead people had lived.
  • This gave him a valuable clue about the cause of the disease.
  • Many of the deaths were near the water pump in Broad Street (especially numbers 16,
  • 37,
  • 38 and 40).
  • He also noticed that some houses (such as 20 and 21 Broad Street and 8 and 9 Cambridge Street) had had no deaths.
  • He had not foreseen this,
  • so he made further investigations.
  • He discovered that these people worked in the pub at 7 Cambridge Street.
  • They had been given free beer and so had not drunk the water from the pump.
  • It seemed that the water was to blame.
  • Next,
  • John Snow looked into the source of the water for these two streets.
  • He found that it came from the river polluted by the dirty water from London.
  • He immediately told the astonished people in Broad Street to remove the handle from the pump so that it could not be used.
  • Soon afterwards the disease slowed down.
  • He had shown that cholera was spread by germs and not in a cloud of gas.
  • In another part of London,
  • he found supporting evidence from two other deaths that were linked to the Broad Street outbreak.
  • A woman,
  • who had moved away from Broad Street,
  • liked the water from the pump so much that she had it delivered to her house every day.
  • Both she and her daughter died of cholera after drinking the water.
  • With this extra evidence John Snow was able to announce with certainty that polluted water carried the virus.
  • To prevent this from happening again,
  • John Snow suggested that the source of all the water supplies be examined.
  • The water companies were instructed not to expose people to polluted water any more.
  • Finally "King Cholera" was defeated.
人教版高三英语必修5 Unit1 Great scientists听力Mp3下载
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人教版高三英语必修5 Unit1 Great scientists听力Mp3下载

年级:初一 时长:38分 学习人数:327837 发布时间:2015-12-06
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