One of the major scientific discoveries which saved tens of millions of people throughout the world, and was without doubt among the most beneficial discoveries of all times, was Dr. Louis Pasteur’s amazing discovery of curing diseases by using the same germ which caused the disease. Dr. Pasteur researched how to cure diseases including rabies. After his invention was wildly successful beyond all expectations, he began to treat other diseases with the same method.
Until today, Dr. Pasteur’s discovery serves as the main basic approach for all kinds of vaccines. This method has also spurred the development of homeopathic remedies (which often involve a medication based on a material that causes symptoms similar to that of the disease), a method that is gaining popularity in the west.
The book “Mavo Shearim” which was written by a person who lived in Dr. Louis Pasteur’s generation, brings the testimony of reliable and respectable people who heard from Dr. Pasteur’s close friend that Dr. Pasteur received the foundation for his revolutionary study from… the Talmud.
How did it happen? Rabbi Dr. Israel Michel Rabinowitz who lived in Paris, was translating the Talmud into French. His translation for Seder Moed reached his friend Dr. Pasteur and aroused the scientist’s curiosity. To his surprise, he discovered this surprising sentence in the Talmudic tractate of Yoma:
“One who was bitten by a rabid dog, should be fed from his liver lobe.” (Yoma 84a)
The surprised doctor immediately launched a series of experiments whose final result was the salvation of tens of millions of people!!
Truly, delve and delve into it (in profound Torah study) because everything (whatever you want to find) is in it! (Avot 5:22)
 The English biologist Edward Jenner had already used vaccination earlier to cure smallpox, but he didn't use the concept as Pasteur later did to cure a host of other diseases. Pasteur recognized Jenner's contribution by calling the process “vaccination” after Jenner's cowpox (vaccinia) experiments used to cure smallpox.
See the Talmud ibid (83b): Five things were said about a rabid dog. Its mouth is open, its saliva is dripping, its ears droop, its tail is between its thighs, and it walks at the side of the road.