How did Pasteur disprove the theory of spontaneous generation with his swan-necked flask?
Pasteur initially poured beef broth into a long necked flask. In the second step he heated the long neck of flask and bent it into an S-shaped curve. He found that microorganisms did not appear in the cool solution even after a long period. Some of such original vessels of Pasteur which were later on sealed did not show signs of contamination even after a period of 100 years.