RECAPITULATION. 137 



very potent maladies, better than the chemical theory of 

 Liebig ; and shows why the earliest cases of an epidemic 

 are commonly the most fatal. 



When I entered upon the task of elucidating for you 

 this very difficult subject, gentlemen, I did not dream of 

 its extent and importance, nor did I suppose that it would 

 have imposed upon me so much research, or inflicted upon 

 you so many lectures. 



I have, therefore, not attempted to account by this the- 

 ory, for the periodicity of malarious diseases, rather for 

 want of time than want of power, and from a desire not 

 to tax too severely your patience. 



The task is now completed. Yet, after all my labor 

 and your polite attention, the theory presented to you, may 

 not be finally demonstrated. But it is the most consistent 

 with the phenomena known at present, and is much better 

 sustained by established facts than any other hypothesis 

 yet presented to the world. It has, therefore, the requisites 

 of a philosophical theory, which, in other and more exact 

 sciences, would be accepted, not to be held as absolutely 

 true, but as, in the present state of our knowledge, the 

 most plausible and convenient explanation of the pheno- 

 mena. 



It has another value. It will revive the inquiry into 

 the causes of fever, by giving to it a new direction, by 

 oflering new points of view, new motives for study and 

 new lights from analogy. If, too, its confirmation or re- 

 futation should give to future inquirers after truth, half 

 the pleasure which I have derived from excursions into 

 this new field of mingled reason and fancy, these Lectures 

 will not have been vainly elaborated. 



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THE END. 



