Bacteriology and antibiotics
There had been tremendous research on microbe’s anatomy, physiology, and its functionality. In 1876, scientist Robert Koch established that microbes can cause disease in animals and humans. During his research he found that blood from cattle that were infected with anthrax always had large numbers of Bacillus anthracis. Later on, Koch transmitted anthrax from one animal (infected one) to another (healthy one) by taking a small sample of blood and later on found that the healthy animal did get sick. This experiment proved that microbes are living organisms that can be easily transmitted between two species and also cause the disease. He also found that he could grow the bacteria in a nutrient-lled culture, inject it into a healthy animal, and cause illness.