Kircher, a Jesuit scholar and polymath, not specifically trained in medicine, was probably the first to employ the microscope in investigating the cause of disease. He mentioned that the blood of plague patients was filled with a “countless brood of worms not perceptible to the naked eye, but to be seen in all putrefying matter through the microscope” (Garrison). He could not have seen the plague bacillus with his low-power microscope, but he probably saw the larger micro-organisms. He was the first to state explicitly the theory of contagion by animalculae as the cause of infectious diseases.

The first catalogue of Kircher's museum collected by Kircher at the Jesuit College in Rome between 1651 and 1680. Digital facsimile from the Internet Archive at this link.

Includes the first recorded experiment in hypnotism in animals.

Extensively illustrated catalogue by Bonanni of the Musaeum Kircherianum, formed in the mid-17th century by the Jesuit polymath, Athanasius Kircher, and housed in the Jesuit Collegio Romano. Reflective of Kircher's polymathic interests, the museum included objects of every kind from many disciplines: antiquities, archaeology, ethnography, natural history, etc., and also included a number of mathematical, scientific, and physical instruments. Components of Kircher's museum were later dispersed to various other museums in Rome, leaving this book as the only record of its contents. Digital facsimile from the Biodiversity Heritage Library at this link.