RE SEARCH IN MEDICINE 15 



cavities of the body previously closed on account of the great mortality 

 due to sepsis. Antisepsis shares with anesthesia, as its discoverer, 

 Lister, shares with Morton, Warren and Simpson, the honor of the 

 great advances surgery has made in the treatment of disease and 

 injuries of the abdomen, thorax and the cranial cavity. Who can com- 

 pute the relief from suffering and the saving of life which may be 

 traced through Lister to Pasteur's laboratory experiments on fermen- 

 tation ? 



The recognition of the principle of asepsis by the surgeons was, 

 then, as we have seen, slow and grudging enough ; among the profession 

 at large the theory of infection as applied to acute diseases gained more 

 slowly still. It was not until 1880 that advance in the knowledge of 

 the bacterial etiology of infectious diseases assumed such definite shape 

 as to attract general attention. As we look back upon this early work 

 we see clearly that one reason for this slow advance was the absence of 

 proper methods of isolating bacteria in what we now call pure cultures. 

 Pasteur and his co-laborers made (1) direct search for bacteria in the 

 secretions, blood or tissue juices, or (2) inoculated fluid media or 

 animals with such material. By the first of these methods it was 

 possible to recognize bacteria if they were especially abundant, as in 

 anthrax, and it was by this method that Neisser discovered the gono- 

 coccus (1879) and Hansen the leprosy bacillus (1879), bacteria which 

 are particularly abundant in the local lesions of the respective diseases. 

 The second method, the use of fluid media, was satisfactory if the mate- 

 rial for study contained only one type of organism ; if more than one it 

 was obviously difficult to study the life history of a bacterium or to 

 obtain exact results by the inoculation on account of the simultaneous 

 growth of associated or contaminating organisms. This difficulty was 

 overcome by Koch, in 1881, through the introduction of solid culture 

 media. Koch had already, while a country practitioner, definitely and 

 clearly established the relation of the anthrax bacillus to the splenic 

 fever of cattle and had demonstrated in this organism the formation of 

 spores and their importance; also he had published most important 

 observations on the bacteriology of wound infection. The use of solid 

 media, which it is said was suggested to Koch by the growth of mould 

 on potato, led at once to rapid advance, for as each bacterium placed 

 on a solid medium causes, as it multiplies, the growth of a visible 

 colony, it was possible to distinguish colonies having different char- 

 acteristics and by transplantation to secure pure cultures. The demon- 

 stration of Koch's solid media and plate method at the Congress of 

 Hygiene in London in 1881 caused Pasteur to exclaim " C'est un grand- 

 progres." This advance and the use of microscopes equipped with the 

 oil immersion lens and the Abbe condenser, and the increased knowl- 

 edge concerning the use of the aniline dyes for staining purposes gave 



