LISTER 11 



Eberth had observed, four years previously. In 1885 Loeffler discovered the 

 bacillus of swine erysipelas, Kitt the bacillus of hsemorrhagic septicaemia of cattle, 

 and Salmon and Smith the bacillus associated with hog cholera. In the same year 

 Nicolaier observed the tetanus bacillus in soil, inoculation of which produced the 

 disease in animals. In 1886 Fraenkel isolated the pneumococcus, Escherich the 

 colon bacillus, and Loeffler the bacillus of swine plague. In 1887 Weichselbaum 

 discovered the meningococcus, and Bruce the micrococcus of Malta fever. In 

 1888 Gaertner described the bacillus which bears his name, and Schlitz the strepto- 

 coccus of equine strangles. In 1889 Kitasato cultivated the tetanus bacillus, 

 which had been earlier observed by Nicolaier. In 1892 Pfeiffer isolated the bacillus 

 which he believed to be the cause of influenza, and Welch and Nuttall described 

 the anaerobic bacillus now known as CI. welchii. In 1894 Kitasato and Yersin 

 independently discovered the bacillus of plague. In 1895 Moore isolated the 

 bacillus of fowl typhoid. In 1896 van Ermengem described CI. botulinum as 

 the cause of a particular variety of food poisoning. In 1897 Bang discovered the 

 bacillus of bovine abortion. In 1898 Shiga isolated the variety of dysentery 

 bacillus which bears his name, and Nocard and Roux described the minute organism 

 of infectious pleuro-pneumonia of cattle. 



Thus, by the close of the nineteenth century a great variety of micro-organisms 

 had been identified as occurring in definite association with human or animal 

 disease. In many instances complete demonstration had been afforded that the 

 relation was one of cause and effect. In others, this relation was rendered highly 

 probable. In others, again, there remained good reason for doubting whether 

 the bacterium, whose presence had been demonstrated, played any more important 

 role than that of a secondary invader. Beyond dispute, however, the scientific 

 investigation of infective disease had become the province of the bacteriologist. 



Another incident had done much to emphasize the importance of bacteria as 

 the cause of disease and death, although it had comparatively little influence on 

 bacteriology itself. Joseph Lister (1827-1912), during his tenure of the Professor- 

 ship of Surgery at Glasgow, was deeply interested in the post-operative sepsis, 

 which exacted such a terrible toll on the lives of hospital patients. His attention 

 was drawn to Pasteur's work on fermentation, and the analogy between the changes 

 which occur in fermenting organic material and the putrefaction which occurs in 

 wounds suggested to him that in the latter, as in the former, the underlying cause 

 might be the activity of minute living organisms. This led directly to the intro- 

 duction of his antiseptic technique in surgery, described in 1867, which opened the 

 door to modern surgical methods. Lister's technique has since been replaced by 

 aseptic measures, but this detracts in no way from the merit of his discovery, 

 nor from the debt which we owe to him for fighting the usual battle against the 

 forces of ignorance and prejudice. Nor should it be forgotten that Lister made 

 important contributions to bacteriological technique as such. He devised a method 

 for diluting a bacterial culture and preparing a series of subcultures with so small 

 a volume of the original fluid that many of them remained sterile, the presump- 

 tion being that those that grew had developed from a single bacterial cell. In 

 this way he isolated, in 1878, a bacterium that caused the souring of milk ; 

 and Bulloch (1938) expresses the view that he may perhaps have been the first 

 bacteriologist to obtain a certainly pure culture. 



But the revolution inaugurated by Pasteur and extended by Koch spread far 

 beyond the field of medicine. Agriculturists had long been puzzling over the 



