plate 4 germ theory. miasma during the 1800s, the miasma theory of disease dominated medical thought...
TRANSCRIPT
Plate 4Germ Theory
Miasma During the 1800s, the miasma theory of disease dominated medical thought
It was believed that disease could be caused by the foul smells created by decomposing bodies, food, human waste, marsh gases and general filth.
Road sweeping was one way to help clean up the streets and hopefully prevent the spread of disease. http://www.sciencemuseum.org.uk/hommedia.ashx?id=7673&size=Small
The ProblemWine did not have consistent flavors from one year to the next
Microscopic examination showed that yeast and bacteria were in spoiled wine and yeast alone in good wine
http://wpcontent.answers.com/wikipedia/commons/f/f6/Kombuchacultsm.jpg
Vinegar
The word "vinegar" comes from the Old French vin aigre, meaning "sour wine".
http://www.touchofeurope.net/linens/Vinegars.html
Pasteur’s Experiment
Pasteur boiled grape juice (w/ yeast) plugged and let cool – no growth
When added just yeast then grape juice turned into good wine so he determined that yeast was necessary for wine
http://www.icbm.de/~palmikro/mikrobiologischer-garten/pics/hefe_ph.jpg
http://www.vinegarman.com/zoo_vinegar_bacteria1.shtml
Bacteria are agents of change – they alone sour wine
Acetobacter aceti bacteria turn alcohol and sugars into acetic acid
Pasteur’s Experiment
Pasteur’s Conclusion• Microorganisms might
be agents that cause disease
• Pasteurization (rapid heating and cooling) retards spoilage by killing all living cells, does not kill spores of bacteria (milk, OJ, many food products)