INFORMATIONAL ITEM
Miasma
The miasmatic
theory of disease held that diseases such as cholera or the Black Death
were caused by a miasma (Greek language: "pollution"), a
noxious form of "bad air." In general, this concept has been
supplanted by the more scientifically founded germ theory of disease.
Miasma
is considered to be a poisonous vapor or mist that is filled with particles
from decomposed matter (miasmata)
that could cause illnesses and is identifiable by its nasty, foul smell (which,
of course, came from the decomposed material). A prominent supporter of the
miasmatic theory was Abaris the Hyperborean, who famously
cleaned Sparta
under
The
miasmatic theory of disease began in the Middle Ages
and continued to the mid 1800s, when it was used to explain the spread of cholera
in London
and in Paris,
partly explaining Haussmann's latter renovation of the
French capital. The disease was said to be preventable by cleansing
and scouring of the body and items. Dr. William
Farr, the assistant commissioner for the 1851
The
theory of miasma made sense to the English sanitary reformers of the
mid-nineteenth century. Miasma explained why cholera
and other diseases were epidemic in places where the water was undrained and
very foul-smelling. The theory led to improvements in the sanitation systems,
which led to decreased episodes of cholera,
which helped to support the theory.
Even
though the miasmatic theory has been disproved by the knowledge of viruses and bacteria,
it made the connection between dirtiness and diseases. This caused public
health reforms and encouraged cleanliness, even though some doctors still did
not wash their hands between patients. They believed that the miasmata were only airborne and would
not be stuck on the doctors' hands.
The
miasmatic theory was consistent with the observations that:
- Disease was associated with poor sanitation
(and hence foul odors) and that sanitary improvements reduced disease, but
not with the observations of microbiology
that led to the germ theory of disease.
CHOLERA
So far
as cholera is concerned, the miasmatic theory was disproved by John Snow following an epidemic in Soho, central London in 1854. Because of the miasmatic
theory's predominance among Italian scientists, the 1854 discovery by Filippo
Pacini of the bacillum that caused the disease was
completely ignored, and the bacteria had to be rediscovered thirty years later
by Robert Koch.
A
remnant of this theory is the name of malaria,
from Italian mala aria ("bad air").
GERM THEORY
The alternative theory, supported by John Snow, held that
cholera was caused by a germ cell, not yet identified. He reasoned that
this germ was transmitted from one person to another by drinking water. Snow's
germ theory was deemed "peculiar" by John Simon, head medical officer
of
Here is a summary written by
"This doctrine is, that cholera propagates itself by a ‘morbid matter' which, passing from one patient in his evacuations, is accidentally swallowed by other persons as a pollution of food or water; that an increase of the swallowed germ of the disease takes place in the interior of the stomach and bowels, giving rise to the essential actions of cholera, as at first a local derangement; and that ‘the morbid matter of cholera having the property of reproducing its own kind must necessarily have some sort of structure, most likely that of a cell."
While Dr. Simon clearly understood John Snow's theory, he
joined others in questioning the relevance of the germ theory to cholera.