It is unclear why Pouchet shifted his interest to spontaneous generation, but in December 1858, Pouchet presented results to the French Academy of Sciences of two experiments he conducted that he claimed supported the notion of spontaneous generation. He said that his results were the opposite of Theodore Schwann’s results that demonstrated spontaneous generation did not exist. Schwann observed that after heating oxygen in a vessel, which was thought to be important for spontaneous generation, no microorganisms grew. He said that this was a result of the germs in the oxygen or air being destroyed by the heat. Pouchet claimed that when he did Schwann's experiment, microorganisms did grow, and thus germs in the air did not produce microorganisms. His experiments did not receive a positive reaction from the academy. Most of them thought his experiments were conducted poorly and that he did not effectively control for the intrusion of germs.