BEFORE BACTERIOLOGY 



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be cultivated outside the body, reproduce the same 

 disease in animals, and be found again in the 

 tissues of those animals. By an immeasurable 

 amount of hard work crowded into a few years, this 

 New World of bacteriology has been subdued. The 

 Royal Commissioners of 1875, speaking of physio- 

 logical experiments only, said, "It would require 

 a voluminous treatise to exhibit in a consecutive 

 statement the benefits that medicine and surgery 

 have derived from these discoveries." If physiology 

 in 1875 required a treatise, bacteriology in 1902 

 requires a shelf : and it is impossible here to give 

 more than the faintest outline of some of the work 

 that has been done. 



But all pathology is not bacteriology ; and it 

 would take a treatise of prodigious length to set 

 forth the work of modern pathology in the years 

 before anything was known of bacteria. The 

 microscopic structure of tumours and of all forms 

 of malignant disease, the nature of amyloid, fatty, 

 and other degenerative changes, and the chief facts 

 of general pathology — hypertrophy and atrophy, 

 necrosis, gangrene, embolism, and many more — 

 all these subjects were studied to good purpose, 

 before bacteriology. Above all, men were occupied 

 in the study of inflammation under the microscope. 

 It was this use of the microscope that revolutionised 

 pathology ; especially, it made visible the whole 

 process of inflammation, the most minute changes 

 in the affected tissues, the slowing and arrest of 

 the blood in the capillaries, the choking-up of the 

 stream, and the escape of blood-cells out of the 



