HISTORY OF MICROBIOLOGY* 



Geronimo Fracastorio, of Verona, was born in 1484, studied medicine 

 in Padua, and published a work in Venice in 1546, which contained the 

 first statement of the true nature of contagion, infection, or disease 

 organisms, and of the modes of transmission of infectious disease. He 

 divided diseases into those which infect by immediate contact, through 

 intermediate agents, and at a distance through the air. Organisms 

 which cause disease, called Seminaria conlagionum, he supposed to be 

 of the nature of viscous or glutinous matter, similar to the colloidal 

 states of substances described by modern physical chemists. These 

 particles, too small to be seen, were capable of reproduction in ap- 

 propriate media, and became pathogenic through the action of animal 

 heat. Thus Fracastorius, in the middle of the sixteenth century, gave 

 us an outline of morbid processes in terms of microbiology. 



Athanasius Kircher, in 1659, demonstrated the presence of " minute 

 living worms in putrid meat, milk, vinegar, etc.;" but he did not 

 describe their form and character, and it is doubtful whether he ever 

 saw microorganisms. 



In the year 1683 Antonius van Leeuwenhoek, a Dutch naturalist and 

 a maker of lenses, communicated to the English Royal Society the re- 

 sults of observations which he had made with a simple microscope of 

 his own construction, magnifying from 100 to 150 times. He found in 

 water, saliva, dental tartar, etc., what he termed "animalcula." He 

 described what he saw, and by his drawings showed both rod-like and 

 spiral forms, both of which, he said, had motility. In all probability, 

 the two species he saw were those now recognized as Bacillus buccalis 

 maximus and Spirillum spuligenum. Leeuwenhoek's observations 

 were purely objective and in striking contrast with the speculative 

 views of M. A. Plenciz, a Viennese physician, who in 1762 published a 

 germ theory of infectious diseases. Plenciz maintained that there 

 was a special organism by which each infectious disease was produced, 



* Prepared by F. C. Harrison. 



