6 HISTORY OF MICROBIOLOGY 



beautiful results by Ehrlich, Koch, Gram, and others. The staining 

 of microorganisms rendered it possible to obtain pictures of them by 

 photographic methods; the art of photomicrography developed thus 

 rapidly. 



In 1879, Miquel discovered bacteria which grew or developed at tem- 

 peratures between 65* and 75. He isolated them first from the waters 

 of the Seine, and subsequently from dust, manure, and other substances. 

 Later researches have shown that these thermophilic organisms play im- 

 portant roles in various fermentations. 



The ninth decade of the last century was prolific in important bac- 

 teriological events. Discovery followed discovery in rapid succession. 

 In 1880, Laveran, a French military surgeon, discovered the protozoon of 

 malaria; in 1881 Robert Koch introduced the poured gelatin and agar 

 plate, which made it possible to obtain pure cultures without difficulty. 

 Investigators were quick to take advantage of this method and notable 

 results followed. Eberth and GafTky discovered the bacillus of typhoid 

 fever, and succeeded in growing it in culture media. In 1882, Loeffier 

 and Schiitz discovered the bacterium which causes glanders ; and in the 

 following year Koch isolated the vibrio of Asiatic cholera from the in- 

 testines of cholera patients. In 1883 Klebs described the diphtheria 

 bacterium; and, in 1884, Loeffler grew the organism in pure culture. 



In 1884, Koch published his results on the etiology of tuberculosis, 

 in a paper which will remain as a classical masterpiece of bacteriological 

 research, owing to the difficulty of the task and the thoroughness of the 

 work. Not only did Koch show the tubercle bacterium by appropriate 

 staining methods, but he succeeded in obtaining pure cultures of it and 

 in producing tuberculosis by inoculation with his isolated cultures. 



In 1885, Nicolaier observed the tetanus bacillus in pus produced by 

 inoculating mice and rabbits with soil; later, in 1889, Kitasato isolated 

 this organism, and showed that the cause of the failure in earlier 

 attempts to isolate it were due to the fact that it could grow only in the 

 absence of free oxygen. The specific infecting agents in pneumonia 

 were discovered by Friedlander and Fraenkel about this time, as were 

 also several organisms associated with inflammation and suppuration, 

 such as the Streptococcus pyogenes and the Staphylococcus pyogenes, 

 discovered by Rosenbach, and the green pus germ (Pseudomonas 

 pyocyanea) by Gessard. 



*A11 temperatures are stated in Centigrade scale, unless otherwise indicated. 



