41 



to the class in question, but by recent research 

 it may be considered as having been rendered 

 evident that they depend upon the introduction 

 of bacilli into the system, to the growth and multi- 

 plication of which are due the phenomena that are 

 observed. Opinion has for some time past been 

 advancing to this point. Our countryman Dr. 

 William Budd devoted special attention to cholera 

 and typhoid fever and in 1849 stood prominently 

 forward in urging that a living microscopic 

 organism constituted the source of the diseases of 

 their kind. For awhile, however, fever germs were 

 only talked about, without their reality being 

 regarded as established. The discussion at the 

 Pathological Society in 1875 on the germ theory 

 of disease marks an epoch in the history of this 

 subject, and shows that up to this time much 

 progress had not been made towards settling the 

 question ; for, whilst some spoke in favour of the 

 theory, no less an authority upon fevers than the 

 late Dr. Murchison expressed himself strongly 

 against it. Since then, knowledge has advanced 

 in great strides ; and, now, not only has the fact 



