Fermentation and Kindred Phenomena* 101 



ludicrous to assume for a moment that a minute organism, 

 quite invisible to the naked eye, could attack and slay in a few 

 hours a huge animal like an ox. But after Pasteur's memorable 

 researches in 1861, on the ferment of sour milk, it was clearly 

 shown that in spite of their minuteness, micro-organisms can 

 produce very marked and extensive effects, even in a large 

 quantity of matter, and Pasteur's work impressed Davaine so 

 strongly with the potency of micro-organisms, that he once 

 more returned to his observations of 185 1, and became impressed 

 with the belief that the bacilli observed in the blood of animals 

 dead of splenic fever were no mere accidental accompaniments 

 of the disease, but its actual cause. 



The hypothesis having been introduced that this particular 

 disease was really the work of micro-organisms, it was only 

 natural that they should be sought for in other ailments of a 

 similar kind, and the result has been a very distinct and impor- 

 tant gain to medical science. It is possible that the new theory 

 has fascinated medical men too much, and that they have too 

 readily convinced themselves that diseases of all kinds are caused 

 by organisms. It must, however, be borne in mind that inves- 

 tigations into the cause of disease are extremely difficult, and 

 that the results are at times extremely uncertain and misleading. 

 I think you will very naturally feel inclined to make this 

 remark — of course I mean if you are not acquainted with the 

 subject. 



It is all very well to say that splenic fever is caused by 

 organisms because they are found in the blood of the animals 

 dead of the disease, but are not organisms almost universally 

 present, and may not their occurrence in the blood of the animals 

 be rather the effect than the cause ? Do not they appear simply 

 because putrefaction (or some modification of it) has already 

 commenced ? 



The question is perfectly fair and logical, and has probably 

 occurred to every one who has thought about the subject. 

 Something more must indeed be shown besides the mere fact 

 of the presence of organisms in the blood or tissues of an animal 

 dead of the disease. In fact before we can credit so startling a 



