CHAPTER III. 



The History of Bacteriology. 



Earliest Workers — Kircher's Contagium Animatum— bacteria, in Fermenta- 

 tion, Putrefaction and Disease — Early Classifications — Miiller — Abio- 

 genesis — Needham — Biogenesis — ^ Bonnet — Spallanzani — Schultz's 

 Experiments — Schwann — Later Experiments — Pasteur — Bastian — 

 Colour and Fermentation — Cohn and Naegeli's Classification — Henle's 

 Researches and Postulates — Pasteur's Researches on Fermentation and 

 Putrefaction — " Flower of Wine " — " Flower of Vinegar " — Bacteria 

 as Scavengers — Pasteur on Silkworm Disease, and Wine Disease — 

 Germs killed by Carbolic acid — Origin of Antiseptic Treatment. 



Since Athanasius Kircher mistook blood and pus corpuscles 

 for small worms, and built up on his mistake a new theory 

 of disease and putrefaction, and since Christian Lange, the 

 professor of Pathological Anatomy in Leipzig, in the preface 

 to Kircher's book (1671) expressed his opinion that the 

 purpura of lying-in-women, measles, and other fevers were the 

 result of putrefaction caused by worms or animalculae, a 

 " Pathologia Animata " has, from time to time, been put 

 forward to explain the causation of disease. Crude as was 

 his theory, and imperfect as were the observations on which 

 it was based, it is marvellous that Kircher, with the simple 

 lenses that he had at his disposal, magnifying only some 

 thirty-two diameters or one thousand times, was able to 

 make out as much as he did. The observations that he 

 made were, naturally enough, not generally credited ; and 

 the theories he formulated were received with chilling in- 

 credulity by most of his contemporaries. 



Remarkable as were Kircher's observations, still more 

 wonderful were those of Anthony Van Leeuwenhoek, a 

 native of Delft in Holland, who in his youth had learned 

 the art of polishing lenses, and who was able, ultimately, to 

 produce the first really good microscope that had yet been 

 constructed. Not only did Leeuwenhoek make his micro- 

 scope, but he used it to such good purpose that he was able 



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