Epidemics. 297 



not of that equal and invariable character observed in the 

 motions of the planetary bodies; and that, at some time or 

 other, some violence has occurred to its internal constitution 

 or mechanism, which has thrown out of order that 

 uniformity of sequences, so much observed in our seasons, 

 and our diseases, yet not to that degree in which general 

 laws cannot be distinctly traced and plainly indicated. 



That violence, or a succession of violent shocks, upon a 

 large and gigantic scale, have occurred to this globe, 

 geology has long since recognized. From the views 

 already given in relation to the earth itself having, from the 

 constant relation of forces within itself, a true and certain 

 effect on vital manifestations on its surface, it will be 

 perceived that no changes, of any great magnitude within, 

 can occur without, in some measure, the vital integrity of 

 objects on its surface being more or less affected ; but 

 changes far greater, and of a more powerful nature, than 

 anything merely going five to ten miles below the sur- 

 face. 



The great question, therefore, is this Is stratification 

 the result of slow and gradual changes, running over a long 

 series of years and ages, till we gradually arrive at the expres- 

 sion of an epoch, may-be, of 1,000,000 years, or twice or three 

 times that time, to be succeeded by another epoch of equal 

 or longer duration ? Or is rock stratification owing to some 

 mighty and much more comprehensive catastrophe, and is 

 the present order of things simply the outcomes of all the 

 good and evil which that mighty change has left to mark 

 its completeness and its existence ? 



To this latter view the writer is disposed to lean, no 

 matter what the enormous difficulties are which appear to 

 stand opposed to it ; and in 1864 he wrote a short tract 

 anonymously, entitled " Doubts Relative to the Epochal 

 and Detrital Theory, by a Near Kinsman of Thomas 



