Civilisation : Its Cause and Cure 



tice of this kind on so great a scale necessarily 

 takes a long period of years, and meanwhile 

 changes are taking place in the habits of the 

 people, Sanitation is being improved, customs 

 of Diet are altering, possibly (as so often happens 

 in the history of an epidemic) the disease, having 

 run its course, is beginning spontaneously to decline. 

 And thus another series of possible causes has 

 to be discussed. 



Then, supposing the question, notwithstanding 

 all these difficulties, to be so far settled in favour 

 of the present system there still arises that 

 whole other series of difficulties with regard to 

 the possibility of the spread of other diseases by 

 the practice, and with regard to the extent of such 

 spread, before we can arrive at any finale. This 

 series of questions is almost as complex as the 

 other ; and it includes that great element of 

 uncertainty the question what interval of time 

 may elapse between inoculation with a disease 

 and its actual appearance. For if in several 

 cases children break out with erysipelas immedi- 

 ately after vaccination, of course there is a certain 

 presumption that vaccination has been the cause ; 

 but if the erysipelas only appears some years 

 after, its connection with the operation may, though 

 real, be impossible to trace. 



The matter standing thus, it seems to us almost 

 a mystery how it was that the medical authorities 

 of the early days of Jennerism were so cocksure 

 of their conclusions until we remember that 

 in arriving at those conclusions they practically 



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