巴斯德的化学实验【英文】

1626 1697
Experiment done in 1668
Francesco Redi’s Experiment Attempting to Disprove Spontaneous Generation
ቤተ መጻሕፍቲ ባይዱ
Common Beliefs of the Time
• Frogs and Turtles come from mud and rotting wood. • Mice come from straw. • Flies come from rotting meat. • Most of these ideas remained from the time of Aristotle. Why would people believe this? The belief that LIFE can come from NON-LIVING things is called:
SPONTANEOUS GENERATION
Redi’s Experiment:
Redi observed that flies often appeared on and around rotting meat. So, he placed rotting meat in three jars.
(this prevented micro-organisms in air from entering flask, yet allowed air to flow freely)
4. If swan neck was broken, microbes entered the flask and grew
Was not accepted as the most plausible theory until 1861, based on experimental data by Louis Pasteur
LOUIS PASTEUR’s experiment:
1. Filled a flask with broth 2. Heated the broth to kill all life 3. Drew out the neck of the flask to make a long S
Step One:
• Jar-1 Left Open • Maggots developed • Flies were observed laying eggs on the meat in the open jar
Step Two:
• Jar-2 Covered with Netting • Maggots appeared on the netting • Flies were observed laying eggs on the netting
Step Three:
• Jar-3 Completely Sealed • No maggots developed
This was the first experiment that proved BIOGENESIS
“Life can only originate from pre-existing life”