The first person to describe red blood cells was the young Dutch biologist Jan Swammerdam, who had used an early microscope in 1658 to study the blood of a frog.
William Harvey discovered the circulation. he first recorded successful blood transfusion occurs in England: Physician Richard Lower keeps dogs alive by transfusion of blood from other dogs. 1656 Sir Christopher Wren experiments with canine blood transfusions
On May 14, 1796, Jenner took fluid from a cowpox blister and scratched it into the skin of James Phipps, an eight-year-old boy. A single blister rose up on the spot, but James soon recovered. On July 1, Jenner inoculated the boy again, this time with smallpox matter, and no disease developed. The vaccine was a success.
Humphry Davy , a British chemist and inventor, described how nitrous oxide (laughing gas) has anesthetic properties
Rene Laennec, a French doctor, invented the stethoscope
Crawford Long , an American pharmacist and surgeon, recognized as the first doctor to have used inhaled ether anesthesia on a patient for a surgical procedure
An Irish physician named Francis Rynd invented the hollow needle and used it to make the first recorded subcutaneous injections in 1844.
Wilhelm Conrad Röntgen produced and detected electromagnetic radiation in a wavelength range; what we call today Röntgen rays or X-rays
Felix Hoffmann, a German chemist, produced a stable form of acetylsalicylic acid, more commonly known as aspirin. Hoffmann, was searching for something to relieve his father's arthritis.
Karl Landsteiner identified the presence of agglutinins in blood and developed the modern system of classifying blood groups
Cook County Hospital in Chicago establishes the first blood bank.
DNA profiling is when specific DNA pattern (profile) is obtained from a person or sample of body fluid