DISSERTATION SECOND. 



SKETCH OF THE PROGRESS OF NATURAL PHILOSOPHY FROM 

 THE REVIVAL OF LEARNING TO THE PRESENT TIME. 



PART SECOND. 



FROM THE COMMENCEMENT OF NEWTON'S DISCOVERIES 

 TO THE YEAR 1818. 



I n the former part of this sketch, the history of each division 

 of the sciences was continued without interruption, from the 

 beginning to the end. During the period, however, on 

 which I am now to enter, the advancement of knowledge has 

 been so rapid, and marked by such distinct steps, that seve- 

 ral pauses or resting-places occur of which it may be advisa- 

 ble to take advantage. Were the history of any particular 

 science to be continued for the whole of the busy interval 

 which this second part embraces, it would leave the other 

 sciences too far behind ; and would make it difficult to per- 

 ceive the mutual action by which they have so much assisted 

 the progress of one another. Considering some sort of sub- 

 division, therefore, as necessary, and observing, in the inter- 

 val which extends from the first of Newton's discoveries to 

 the year 1818, three different conditions of the Physico- 



