Epidemics. 233 



essential in accounting for some of our zymotic diseases. 

 But for cancers, consumption, etc., it is not essential as a 

 primary starting-point that we admit an ascending scale of 

 cell development ; but the degradation of a higher cell 

 development to some lower and yet more independent 

 condition of cell development, which, from undergoing the 

 transformation into a lower form, or degradation of develop- 

 ment, especially in cancer, is more persistent in its increase 

 of growth. 



The very nature of this rapid outline, or sketchy allusion 

 to many important matters, necessarily excludes the idea of 

 a lengthened examination, or attempted defence, of subjects 

 so replete with interest, and yet so obscure in tracing the 

 data and groundwork of the assumption so concisely given ; 

 but the suggestion must be allowed to suffice for the 

 present. 



Concerning the present epidemic epoch, from 1817 to 

 2457, or thereabouts, it will be said that, calculating from 

 the past, much might be suggested for the future ; but 

 there is an old saying, " Least said the soonest mended,'* 

 therefore as little will be said as possible, consistent 

 with a very patient review of the leading facts, or 

 at least a very fair share of them, the chief source of 

 which knowledge has come from reading the present 

 literature of the day, of which none is more admirable for 

 so complete an index to disease as that supplied to us 

 through our weekly, monthly, and quarterly medical 

 periodicals. Here and there some author stands boldly out 

 to claim a passing consideration who appears, in a measure, 

 more prominent and bewitching in his style, or more terse 

 and comprehensive in his matter, than perhaps the current 

 periodical literature of the day can lay claim to ; yet even 

 here much has first gained its way to the public by appear- 

 ing in periodical literature. Perhaps such authors as 



