Disease

For several centuries, people though diseases were caused by wandering clouds of poisonous vapor. We now know that this theory is pretty ridiculous, and that diseases are caused by specific bacteria. But how did we get to this new idea of germ theory? Tien Nguyen describes the work of several scientists who discredited a widely accepted theory in a way that was beneficial to human health.

Watch the video How a few scientists transformed the way we think about disease by Tien Nguyen, that was created with support from the U.S. Office of Research Integrity: http://ori.hhs.gov.

Miasma theory

Have you heart anything about Miasma theory ?

miasma /maɪˈæzmə/ (usually singular) means a heavy cloud of something unpleasant or unhealthy:
A miasma of smog settled over the city.
The origin of the word miasma is New Latin, from Greek, defilement, from miainein to pollute, the first known use was in 1665.

This word (plural miasmas also miasmata \-mə-tə\) can be used for a vaporous exhalation formerly believed to cause disease.

In miasma theory, diseases were caused by the presence in the air of a miasma, a poisonous vapour in which were suspended particles of decaying matter that was characterised by its foul smell. The theory originated in the Middle Ages and endured for several centuries. That a killer disease like malaria is so named - from the Italian mala‘bad’ and aria ‘air’ - is evidence of its suspected miasmic origins.

In notes taken during a voyage to South America on HMS Beagle in the 1830s, Charles Darwin described an illness that he believed was caused by "miasma" emanating from stagnant pools of water. For him, "miasma" had the same meaning that it did when it first appeared in English in the 1600s: an emanation of a vaporous disease-causing substance. But while Darwin was at sea, broader applications of "miasma" were starting to spread. Nowadays, we know germs are the source of infection, so we're more likely to use the newer, more figurative sense of "miasma," which refers to something destructive or demoralizing that surrounds or permeates.

miasmal 

\-məl\ adjective

miasmatic 

\ˌmī-əz-ˈma-tik\ adjective

miasmic 

\mī-ˈaz-mik, mē-\ adjective

miasmically 

\-mi-k(ə-)lē\ adverb

Hermann J. Muller

Hermann Joseph Muller was born in New York City on December 21, 1890. His grandparents on his father's side were of artisan and professional background and, though at first Catholics, had emigrated from the Rhineland during the wave of reaction of 1848 to seek the greater freedom of America.

He first discovered that genetic mutations can be induced through the use of X-rays, and he demonstrated that mutations are the result of breakages in chromosomes and of changes in individual genes. The Nobel Prize he got in 1946 for this discovery increased his opportunities to publicize the dangers posed by accumulating spontaneous mutations in the human gene as a result of industrial processes and radiation. He also promoted an idea of sperm banks of gifted men in order to preserve the quality of man’s life for the future.