Inventions and discoveries transformed the practice of medicine in the 1800's. In all three major areas of medical work—prevention, diagnosis, and treatment—new methods led to important breakthroughs. The French scientist Louis Pasteur established the effectiveness of inoculations as a means of preventing disease. An injection administered by Pasteur's assistant— with Pasteur himself watching in the background—saved a young man who had been bitten by a rabid dog (right).
Once a problem arose, the remarkable new technique of X-ray photography allowed a doctor to diagnose the problem inside the body. Then, thanks to the invention of anesthetics, a surgeon could remedy the problem by painlessly operating on the patient.
