CHAPTER ONE SPONTANEOUS NOTHING ABOUT IT Louis Pasteur had been studying tiny creatures called microorganisms for years He was not alone By 1859 they were a subject of heavy debate Scientists were trying to determine where they came from A leading theory was spontaneous generation This is the idea that life can come from nonliving matter Early experiments seemed to show the idea was true In the 1600s Scientists intensely studied microorganisms in the 1800s but many questions about these tiny creatures remained 5
scientist Jan Baptist van Helmont set out a jar filled with dirty cloth and corn Mice soon appeared in the jar He believed they had come from the materials in the jar He did not realize they already existed They simply were attracted to the jar People began questioning spontaneous generation before Pasteur’s time In 1668 an Italian named Francesco Redi attacked the idea He performed an experiment to disprove it Redi placed meat in three jars The first was open The second was partially sealed The third was fully sealed If spontaneous generation were real flies and maggots should have been found in all three But only the open jar had flies Challenges Redi’s experiment was a step forward However some thought it was too specific They believed his results might apply only to meat English scientist John Needham tried a similar experiment in 1745 He used a broth mixture Needham boiled the liquid 6
In addition to studying spontaneous generation Redi was a doctor and a poet and sealed the containers The liquids became cloudy showing microorganisms growing inside Needham believed this was proof of spontaneous generation But in 1768 another Italian scientist tested the theory Lazzaro Spallanzani believed Needham’s liquid was contaminated before the container was sealed 7
