V. The Modern Period, 1789–1914 > B. The French Revolution and Europe, 1789–1914 > 7. Western and Central Europe, 1848–1914 > a. Social, Cultural, and Economic Trends > 4. Science and Learning > b. Chemistry, Biology, and Geology > 1882
  PREVIOUS NEXT  
CONTENTS · SUBJECT INDEX · BIBLIOGRAPHIC RECORD
  The Encyclopedia of World History.  2001.
 
 
1882
 
Robert Koch (1843–1910) described the etiology of the tubercle bacillus. This discovery led him (1884) to state Koch's postulates, a method of isolating microorganisms and proving that they are specific causes, not merely concomitants, of disease.  1
 
1883
 
Ilia I. Mechnikov (1845–1916) described the action of phagocytic cells in transparent starfish larvae. His discovery led to a general explanation of local inflammation.  2
 
1883
 
Edouard van Beneden (1845–1901) described how the chromosomes are derived in equal numbers from the conjugating germ cells. This led to the discovery of reduction division in the formation of the gametes.  3
 
1887
 
Svante A. Arrhenius (1859–1927) announced his theory of electrolytic dissociation, according to which most of the molecules of an electrolyte are immediately dissociated into two ions when dissolved.  4
 
1888–91
 
Wilhelm Roux (1850–1924) destroyed half of the two-cell stage of a frog's embryo (1888). The remaining cell developed into half an embryo. In 1891 Hans Driesch (1867–1941), working with sea urchin embryos, got results contradictory to Roux's. This drew attention to the relative roles of the internal and external environments on the development of cells.  5
 
1890
 
Emil von Behring (1854–1917) and Shíbasaburo Kitasato (1856–1931) demonstrated that the serum of immunized rabbits neutralized the toxin of tetanus. This discovery opened the possibility that disease could be prevented through the stimulation of specific antibody production.  6
 
1892
 
August Weismann (1834–1914) described in Das Keimplasma his theory of the continuity of the germ plasm and a scheme for the unfolding of a particulate hereditary pattern in embryogenesis.  7
 
1893
 
Theobald Smith (1859–1934), in “Investigations into the Nature, Causation and Prevention of Southern Cattle Fever,” demonstrated that parasites could act as vectors of disease.  8
 
1895
 
Wilhelm K. Röntgen (1845–1923) discovered x-rays and immediately realized that his discovery had a practical application in medicine.  9
 
1897
 
Eduard Buchner (1860–1917) discovered that zymase, a cell-free yeast extract, caused fermentation, thus resolving a long-standing controversy over “vital” and “inorganic” ferments.  10
 
1900
 
Hugo de Vries (1848–1935), Carl Correns (1864–1933), and Erich Tschermak (1871–1962) independently rediscovered the 1865 work of Gregor Mendel while searching the literature to confirm their own experimental results.  11
 
1903
 
Walter S. Sutton (1876–1916) pointed out that the Mendelian ratios could be explained by the cytological behavior of the chromosomes.  12
 
 
 
The Encyclopedia of World History, Sixth edition. Peter N. Stearns, general editor. Copyright © 2001 by Houghton Mifflin Company. Maps by Mary Reilly, copyright © 2001 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

CONTENTS · SUBJECT INDEX · BIBLIOGRAPHIC RECORD
  PREVIOUS NEXT