“Never, surely, could a man have found himself in a position less favourable for scientific research – poor, humble, unknown, isolated from sympathy and from the scientific appliances which are the necessary tools of the investigator.  Yet he was a man of too strong a character to allow himself to be warped by the position in which he found himself, or to be diverted from the line of work which was most congenial to his nature.”
                          — Sir Arthur Conan Doyle (speaking of Robert Koch)

Robert Koch
First man to prove Bacillus anthracis was the direct cause of a disease

In 1876, Robert Koch discovered and documented the complete life cycle of Bacillus anthracis, the bacteria responsible for causing anthrax.  He also conducted extensive studies on tuberculosis, malaria, and cholera.  Not only was he the recipient of many awards during the course of his lifetime, but Koch also remains immortalized in countries around the globe, as in the statue seen in the picture at the right.  In 1905, Koch also had the honor of receiving the Nobel Prize in Physiology or Medicine. 

           A country doctor with no formal research training, Robert Koch certainly did not seem a viable candidate for making one of the most earth-shattering discoveries in his time.  He began his studies of anthrax in 1873, and everything quickly advanced from there.  He chose to study anthrax because in the area that he lived in, many of the livestock were plagued by anthrax.  Because of this, he decided to set out to discover scientifically what causes the disease known as anthrax.  The advantages of studying anthrax for Koch include that the spores were relatively large and easily seen even with the microscopes that were at his disposal. Inoculating animals at this time in history was not a problem, making establishing a “good” experiment easy.  Also, once animals became completely infected, the bacteria could be found in the blood in such high numbers that it was relatively easy to obtain a sample with a sufficient supply of  anthrax.  Because so little was known about anthrax, and it was quickly becoming of economic concern with the infection of more and more animals, doctors began to research the origins and source of infection. 

           On April 12, 1874, Koch made his first observations suggesting the formation of anthrax spores.  His first recorded observations concerning anthrax spores are as follows: “ The bacteria swell up, becoming shinier, thicker, and much longer. Slight bends develop, and eventually a thick felt develops.  Within the long cells, cross walls appear and small transparent points develop at regular intervals.”  He soon discovered that the stages of Bacillus anthracis range from short bacillus rods to long sporulating filaments to free spores.  Once he discovered the presence of spores, the rest of his preliminary experiments were centered around actually discovering the spore form during the developmental stages of anthrax.

           There were two different methods Koch used to complete his experiments.  Inoculation of mice made his studies possible, and he eventually learned that using the aqueous humor of an animal’s eye could be used to conduct experiments as well.  It permitted growth of the bacteria and formation of spores.  The only requirements necessary for the latter type of experiments was that oxygen was needed and the temperatures had to be between thirty and thirty-five degrees Celsius.

           Robert Koch’s research and findings were so thorough and accurate that today they are still considered almost completely correct.  During his many years of research, Koch developed a list of postulates that he found correct.  They include the following:  (1) a specific microorganism is always associated with a given disease, (2) the microorganism can be isolated from the diseased animal and grown in pure culture in the laboratory, (3) the cultured microbe will cause disease when transferred to a healthy animal, and (4) the same type of microorganism can be isolated from the newly infected animal.