IN" THE LAST HALF-CENTURY. 17 



disappear if man's shaping and guiding 

 hand were withdrawn. Every mechanical 

 artifice, every chemically pure substance 

 employed in manufacture, every abnor- 

 mally fertile race of plants, or rapidly 

 growing and fattening breed of animals, 

 is a part of the new Nature created by sci- 

 ence. Without it, the most densely popu- 

 lated regions of modern Europe and Amer- 

 ica must retain their primitive, sparsely 

 inhabited, agricultural or pastoral con- 

 dition ; it is the foundation of our wealth 

 and the condition of our safety from sub- 

 mergence by another flood of barbarous 

 hordes ; it is the bond which unites into a 

 solid political whole, regions larger than 

 any empire of antiquity; it secures us 

 from the recurrence of the pestilences and 

 famines of former times ; it is the source 

 of endless comforts and conveniences, 

 which are not mere luxuries, but conduce 

 to physical and moral well-being. Dur- 

 ing the last fifty years, this new birth of 



2 



