The first microscope was recorded in 1590 - by the end of the 17th century they were well established and it was well known that things could be seen but not exactly what they were or what they did. The work on identifying bacteria and proving the connection between them and the disease was not done until the end of the 19th century. A German physiologist, Robert Koch, worked first on anthrax and then on TB (consumption) and in 1882 (March 22nd) he produced absolute proof of the existence of Mycobacterium tuberculosis and the fact that it caused TB. He was awarded the Nobel Prize for Medicine in 1905.