The Battle of Needham and Spallanzani
As stated before, Spallanzani lived in exciting time where science was moving beyond what could just been seen with the human eye. The microscope was developed in the 1500s, but was not used extensively until that late 1600s and 1700s when Leeuwenhoek began his studies that would eventually end in the discovery of microorganisms.
Spallanzani’s scientific peer, John Needham, concluded through his own research that microorganisms generate spontaneously through an inherent force. Needham ran an experiment where he found microorganism to generate in mutton gravy, even after being heated a sealed. He sent his findings to The Royal Society, who credited him. Spallanzani heard of the theory and choose to explore the side of his fellow Italian scientist, Redi. Before even experimenting, Spallanzani knew that there was a definite order to the generation of these “little animals” and it was not possible for such beings to simply generate out of thin air.
Spallanzani’s scientific peer, John Needham, concluded through his own research that microorganisms generate spontaneously through an inherent force. Needham ran an experiment where he found microorganism to generate in mutton gravy, even after being heated a sealed. He sent his findings to The Royal Society, who credited him. Spallanzani heard of the theory and choose to explore the side of his fellow Italian scientist, Redi. Before even experimenting, Spallanzani knew that there was a definite order to the generation of these “little animals” and it was not possible for such beings to simply generate out of thin air.
Round 1: The Case of the Mysterious "Little Animals"
Spallanzani went through several series of testing in order to disprove the theory of spontaneous generation. He first set about to try the meat and maggot experiment with his own hands. He placed a piece of meat in a jar without a covering and one with a covering. he observed maggot growth on only the meat without the covering on the jar. Spallanzani then took his work a step further to challenge Needham directly by performing his own experiment. Spallanzani followed the same steps Needham took with the exception that he boiled the flasks containing the mutton gravy for a longer period of time. To his immediate discontent, Spallanzani found microorganisms in his mixture. However, from this discovery he found out that the “little animals” he observed were derived from the air; this air was able to enter the flask even though they were corked. Round one goes to Spallanzani!
Round 2: The Force
In response to the challenge of Spallanzani, Needham and his partner Buffon came up with the theory of Vegetative Force. Needham claimed that the Vegetative Force, the mysterious power which produced life from lifeless materials, was damaged from the prolonged boiling of the flasks in Spallanzani’s experiment. Again, with his natural instinct to discover the truth, Spallanzani chose to challenge Needham again. Spallanzani ran the experiment with the same parameters but choose to melt the top of his flasks in order to seal the liquid inside. From the results of his new experiments he concluded that the flasks that were boiled for minutes would have microorganisms present while the ones boiled for longer period of time would not. Spallanzani realized that some of these animals were still present because they were heat resistant and need much more than an hour of boiling to kill them. Round two goes to Spallanzani!
Round 3: Damaged Air
Feeling that his scientific discovery was in trouble, Needham made one last attempt to derail Spallanzani. In order to take down Spallanzani, Needham stated that by boiling the flasks he damaged the elasticity in the air which would therefore lead to the lack of growth in the flasks. Spallanzani again ran the same experiment as before, except he melted the flasks shut. Upon returning to the boiled flasks, he began to crack the tops on and heard the sound of air rushing. Spallanzani began to worry if Needham was right and taking the upper hand, but, all of a sudden it came to him, his flasks had a wide neck. The flasks Spallanzani used took a lot of heat to melt the glass, this heat drove the air out of the bottle which would explain the small “whhhiisstt” noise he heard. To prove that he was right he used flasks with smaller necks and upon opening them there were no microorganisms found. Spallanzani took down Needham and spontaneous generation through thorough testing, patience, and determination. Final round goes to Spallanzani! Match over!
On to Better and Bigger Things
After wining over the respect of the scientific community, Spallanzani moved on to study animal reproduction and generation in depth. In later experiments, aided by observations, Spallanzani discovered that animals reproduced with reproductive organs with semen and ovum. In addition to this, he performed the first in-vitro fertilization and artificial insemination. He later moved on to study newts and their ability to regenerate specific parts of their body.