What did lazzaro spallanzani invented?

Lazzaro Spallanzani (1729-1799) was an Italian scientist and naturalist. He made several important contributions to biology, including:

- He demonstrated that microorganisms can be killed by heat. Spallanzani boiled broth for various lengths of time and then sealed the broth in glass flasks. He found that the broth remained sterile if the flasks were left undisturbed, but if he tilted the flasks so that the broth came in contact with the air, the broth quickly became cloudy with microorganisms. This experiment showed that microorganisms are not spontaneously generated, but rather come from pre-existing microorganisms.

- He showed that bats use echolocation to navigate in the dark. Spallanzani blinded bats and then released them in a room. He found that the bats were still able to fly around and avoid obstacles, demonstrating that they were using echolocation to navigate.

- He studied the process of digestion. Spallanzani swallowed various objects, such as pieces of meat and metal, and then used a stomach tube to collect the contents of his stomach at different time points. He found that the stomach produced acids that broke down the food into a liquid that could be absorbed by the body.