Read the biographies of any two scientists. Write about them in short and show your compositions to your teacher.

Louis Pasteur: He was a French microbiologist born in 1822. He discovered pasteurization, fermentation process, principle of vaccination etc. He found Germ theory of disease along with Robert Koch. He is regarded as father of microbiology. He discovered vaccine for rabies and anthrax. He show that many microbes spoil beverages like alcohol, beer, milk etc. So he invented a process called pasteurization where liquids like milk is heated to 60-100^oC where most microbes get killed and then cooled suddenly. This process prevents the spoilage of liquids like alcohol, milk etc. He founded an institute which bears his name. He has worked a lot on sericulture too.

Jonas Salk- He was an American scientist who discovered vaccine for polio. He was born on October 28 1914 in New-york. He conducted research on polio virus and developed a killed virus vaccine. During his experiment he vaccinated himself, his wife and sons. Then it was approved by National foundation for Infantile paralysis for general use in 1955. Preliminary testing of this vaccine was done in 1952 where the shot was given to children. Later this vaccine was prepared from live virus. He was awarded for his magical discovery against polio virus.