Mary had just returned from her school. She was thirsty. “Mary, you can have a cup of milk," called her mother. Mary went into the dinning hall. “Mummy, the milk is spoilt," she cried out. Her mother came in. “Let me see. Yes. This milk is spoilt," her mother said. She took out a sachet from the cupboard. “See, Mary, the milk in the sachet is alright," she said. Mary could not understand. The milk got from the milk vendor in the morning got spoilt. But the sachet got from the supermarket was still good. How is that? She asked her mother the reason for this. Her mother explained, “The sachet milk is pasteurized. The milk got from the milk vendor is not pasteurized one." 

 

“But what is the meaning of pasteurized," asked Mary. “Pasteurizing is a scientific method. Fresh milk is boiled to a high degree. Then it is cooled rapidly. In this process the germs in the milk get killed. This was first done by Louis Pasteur. His name is given to this process." 

 

Who is Louis Pasteur? Louis Pasteur was a chemist. He was born in 1822 in a town in France. His parents were not rich. But they gave him a good education. He secured a degree in science. His marks in Chemistry were not high. But his interest in Chemistry made him continue his studies in Chemistry. He spent lot of time in the laboratory. He was continually looking through a microscope at the germs. His professor made a fun of him. “They are useless to man. You are wasting your time," he said. But Pasteur replied, “Sir, the germs cause sickness. I must find out which germs cause which disease?" 

 

“Where do germs come from?" asked his professor. 

 

“Sir, that I must find out" replied Pasteur. 

 

And Pasteur found out after a long and patient work. The germs are present in water, earth, dust and even in the air we breathe. These germs turn milk sour. Milk is a carrier of germs. These germs can cause diseases like tuberculosis and typhoid. He made many experiments. Finally he found out the method to kill the germs in the milk. 

 

Pasteur did not stop with milk. He continued his research. Anthrax, diphtheria and rabies were terrible diseases. Pasteur found out certain vaccines. These vaccines can prevent and cure these terrible diseases. 

 

One day a mother brought her son, Joseph, to Pasteur. Joseph had been bitten by a mad dog. He had been fourteen wound all over his body. The dog had rabies. Every one felt sorry for the boy. They said, “The child is sure to die." Even Pasteur had no hopes. But he had decided to save the boy. 

 

Pasteur had prepared a serum from a rabbit. The rabbit had died of rabies. He injected the serum into the boy’s body, at first small quantities. Slowly, he increased the dosage. On the ninth day Joseph showed improvement. He was out of danger. In three months time, Joseph walked out of the hospital. He then became a perfectly healthy child. The year was 1885. Many had been bitten by mad dogs. But no one had escaped death.