1700 - 1900: The Miracle of Life and Death Appears Smaller . . .
The empirical method and the industrial revolution brought
monumental changes to farming and industry, while the biological
sciences were inspired by the work of Darwin and
microbial nature of many diseases was established. Mendel toiled in
obscurity with his pea plants.
1701 Giacomo Pylarini in Constantiople practiced
"inoculation"--intentionally giving children smallpox to prevent a
serious case later in life. Inoculation will compete with
"vaccination"--an alternative method that uses cowpox rather than
smallpox as the protecting treatment--for a century.
1724 Cross-fertilization in corn was discovered.
1748 Turbevill Needham heated various soups or "infusions"
all of which eventually teem with life; he concluded "there is a
vegetative Force in every microscopical Point of Matter..." in support
of the idea of spontaneous generation.
Farmers in Europe increased their cultivation of leguminous crops and
began rotating crops to increase yield and land use.
Edward Jenner published his book comparing vaccination (intentionally
infecting humans with cowpox to induce resistance to smallpox) to
inoculation (intentionally infecting humans with a putatively mild
strain of smallpox to induce resistance to severe strain of the
disease). He derived his ideas from observing that people who had been
exposed to cowpox were not vulnerable to smallpox. (Vaccine comes
from the Latin word vaccinus - "from cows.")
1799 Lazaro Spallanzani described ingeniously crafted
experiments using "hermetically sealed" flasks heated in boiling water
to test the possibility of using heat to kill all the microbes in an
"infusion" (liquid growth medium).
1809 Nicolas Appert devised a technique using heat to can
and sterilize food, winning a 12,000 franc prize from Napoleon, first
offered in 1795.
Recognizing the importance of agricultural diversity, the Tariff Act
excluded foreign plants and trees from U.S. import duties.
President John Quincy Adams instructed U.S. consular officers abroad
to ship back to the U.S. any plant "as may give promise, under proper
cultivation, of flourishing and becoming useful."
The worldwide search for the elusive mammalian egg ended with the
first observation of canine eggs.
Congress invested $1,000 in the Congressional Seed Distribution
Program, administered by the U.S. Patent Office, to increase the
amount of free seeds mailed to anyone requesting them.
Horse drawn harrows, seed drills, corn planters, horse hoes, 2-row
cultivators, hay mowers, and rakes became popular in Europe and in the
U.S. Industrially processed animal feed and inorganic fertilizer were
1850 Ignaz Semmelweis used epidemiological observations to
propose the hypothesis that childbed fever can be spread from mother
to mother by physicians. He tested the hypothesis by having
physicians wash their hands after examining each patient. He became
despised by the medical profession and lost his job.
Paris hosted an international "Corn Show," featuring corn varieties
from many countries, including Syria, Portugal, Hungary, and Algeria.
1856 Karl Ludwig discovered a technique for keeping animal
organs alive outside the body, by pumping blood through them.
In contrast to the ideas of Justis Liebig,
Louis Pasteur (1822 -
1895) asserted that microbes are responsible for fermentation. His
experiments in the ensuing years proved that fermentation is
the result of activity of yeasts and bacteria.
Charles Darwin (1809 - 1882) hypothesized that animal populations
adapt their forms over time to best exploit the environment, a process
he referred to as "natural selection." As he traveled in the Galapagos
Islands, he observed how the finch's beaks on each island were adapted
to their food sources. He theorized that only the creatures best
suited to their environment survive to reproduce. Darwin also
inferred the process of adaptive radiation, wherein populations spread
out into the environment to exploit specialized resources.
Charles Darwin's landmark book, "On the Origin of Species," was
published in London. It effectively drowned out all other scientific
The Organic Act established the U.S. Department of Agriculture (USDA)
- formerly the Division of Agriculture in the Patent Office - and
directed its commissioner "to collect new and valuable seeds and
plants . . . and to distribute them among agriculturalists."
Also in the US, the Morrill Act established the "land-grant" colleges
of agriculture and mechanical arts. Each state is given money raised
from the sale of federal lands to start and support the colleges.
Louis Pasteur invented
the process of pasteurization, heating wine sufficiently to inactivate
microbes (that would otherwise turn the "vin" to "vin aigre" or "sour
wine") while at the same time not ruining the flavor of the wine.
Anton de Bary proved that a fungus causes potato blight. A challenge
for scientists during this period was to discern whether a microbe was
the cause of, or the result of, a disease.
that decayed organisms are found as small organized 'corpuscles' or
'germs' in the air.
(1822 - 1884), an Augustinian monk, presented his laws of heredity to
the Natural Science Society in Brunn, Austria. Mendel proposed that
invisible internal units of information account for observable traits,
and that these "factors" - which later became known as genes - are
passed from one generation to the next. Mendel's work
remained unnoticed, languishing in the shadow of Darwin's more
sensational publication from five years earlier, until 1900, when Hugo
de Vries, Erich Von Tschermak, and Carl Correns published research
corroborating Mendel's mechanism of heredity.
investigated silkworm disease and established that diseases can be
transmitted from one animal to another.
Joseph Lister began using disinfectants such as phenol (=carbolic
acid) in wound care and surgery as
the germ theory of disease.
Davaine used heat treatment to cure a plant of bacterial infection.
Fredrich Miescher, a Swiss biologist, successfully isolated nuclein, a
compound that includes nucleic acid, from pus cells obtained from
discarded bandages. Meischer, however, was not investigating
heredity. Instead, he was trying to identify the chemicals in cells.
Several generations of scientists would pass before the connection
would be made between the DNA found by Miescher and the laws of
heredity described by Mendel just
three years previously.
1870 W. Flemming discovered mitosis.
DNA was isolated from the sperm of trout found in the Rhine River.
Darwin published "The Descent of Man and Selection Relation to Sex"
applying his ideas of evolution to the origins of humans.
Ernst Hoppe-Seyler discovered invertase, an enzyme that cuts the
disaccharide sucrose into glucose and fructose. The enzyme is still
widely used today in making sweeteners.
Robert Koch investigated anthrax and developed techniques to view,
grow, and stain organisms. He then photographed them, aided by Gram,
Cohn, and Weigart.
1875 Charles Darwin proposed the idea of "gemmules" as a
mechanism of inheritance.
1878 Joseph Lister described the "most probable number"
technique, the first method for the isolation of pure cultures of
bacteria, an important step in understanding infectious diseases.
Ralph Waldo Emerson suggested that weeds were actually plants "whose
virtues have not yet been discovered."
In Michigan, Darwin-devotee William James Beal developed the first
clinically controlled crosses of corn in search of colossal yields.
Albrecht Kossel began his studies of nuclein, leading to his
discovery of nucleic acids.
Studying fowl cholera, Pasteur
published his work on "attenuated" or weakened strains of organisms
that could not cause disease but protected against severe forms of the
The power of the steam engine was harnessed to drive combine
1881 Robert Koch described bacterial colonies growing on
potato slices, on gelatin medium, and on agar medium. Nutrient agar
became a standard tool for obtaining pure cultures and for identifying
genetic mutants. This is considered by T.D. Brock to be the single
most important discovery in the rise of microbiology.
Pasteur used attenuation to develop vaccines against the bacterial
pathogens of fowl cholera and anthrax; this was a founding moment in
immunology and opened new areas in the field of preventive medicine.
1882 Walther Flemming reported his discovery of chromosomes
Robert Koch, using guinea pigs as an alternative host, described the
bacterium that causes tuberculosis in humans. Koch became the first
uncover the cause of a human microbial disease. He established that
specific diseases are caused by specific organisms.
Ilya Metchnikoff observed phagocytes surrounding microorganisms in
starfish larvae. Later, he developed a cell theory to explain the
action of vaccines.
A Swiss botanist, Alphonse de Candolle, recorded the first extensive
study on the origins and history of cultivated plants. His work later
played a significant role in J. J. Vavilos' mapping of the world's
centers of diversity.
August Weismann, a German physiologist, coined the term "germ-plasm."
He asserted in his book of the same name that the male and female
parent contribute equally to the heredity of the offspring; that
sexual reproduction thus generates new combinations of hereditary
factors; and that the chromosomes must be the bearers of heredity. His
books were translated promptly into French and English.
Francis Galton coined the term "eugenics" referring to the science of
improving the human condition through "judicious matings."
1884 Robert Koch stated his "postulates" for testing whether
a microbe is the causal agent of a disease.
a rabies vaccine.
Christian Gram described the differential staining technique for
bacteria known as the Gram stain.
Gregor Mendel died
after 41 years of meticulously studying the heredity "factors" of pea
plants. Having received no scientific acclaim during his lifetime, he
said not long before his death, "My time will come."
The first human trials of
rabies vaccine took place.
Koch, Petri, Loffler, Yersin, and Erlich identified a host of human
Emil von Behring developed the first antitoxin, for diptheria.
J.C. Arthur demonstrated that pear fire blight is a bacterial disease.
1887 Edouard-Joseph-Louis-Marie van Beneden discovered that
each species has a fixed number of chromosomes; he also discovered
the formation of haploid cells during cell division of sperm and ova
R.J. Petri described the circular glass plates with overlapping
glass lids for growing microbes on nutrient agar. Petri plates are
still standard tools of the microbiologist.
Institute was opened in Paris.
Ivanovsky reported that the causal agent of the tobacco mosaic disease
is transmissible and can pass through filters that trap the smallest
bacteria. Such agents are later called "filterable viruses" or just
The self-propelled tractor was introduced.
Researchers at the Lister Institute isolated the diphtheria antitoxin.
Winogradski demonstrated nitrogen fixation in the absence of oxygen by
Wilhelm Kolle, a German bacteriologist, developed cholera and typhoid
E.B. Wilson elaborated on August Weismann's chromosome theory of
Eduard Buchner demonstrated that fermentation can occur with an
extract of yeast in the absence of intact yeast cells. This is a
founding moment in biochemistry and enzymology.
Friedrich Loeffler and P. Frosch reported that the pathogen of the
foot-and-mouth disease of cattle is so small it passes through filters
that trap the smallest bacteria; such pathogens came to be known as
Ronald Ross discovered Plasmodium, the protozoan that causes malaria,
in the Anopheles mosquito and showed the mosquito transmits the
disease agent from one person to another.
1899 Beijerinck's research on tobacco mosaic disease
confirmed the work of Ivanovsky. Beijerinck proposed that the virus
becomes incorporated into the protoplasm of the host plant.
Walter Reed established that yellow fever is transmitted by
mosquitoes, the first time a human disease was shown to be caused by a
Compiled from various sources, including:
Brock, Thomas D. 1961. Milestones in Microbiology. Science Tech
Publishers. Madison, Wisconsin. Pp. 273.
Brock, Thomas D. 1990. The Emergence of Bacterial Genetics. Cold
Spring Harbor Laboratory Press. Cold Spring Harbor, New York. Pp.
Bunch, Bryan and Hellemans, Alexander. 1993. The Timetables of
Technology. Simon & Schuster. New York, New York. Pp. 490.
Hellemans, Alexander, and Bunch, Bryan. 1988. The Timetables of
Science. Simon & Schuster. New York, New York. Pp. 660.
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