AMERICAN PUBLISHER'S NOTICE. 



THE present edition, like the previous American reprints, has 

 been passed through the press under the supervision of Dr. 

 RICHARD J. DUNGHLISON, who has carefully corrected whatever 

 errors had escaped the attention of the author, and has made such 

 changes in the typographical arrangement as seemed calculated to 

 render the volume more convenient for consultation and reference. 

 A few illustrations have also been introduced in the introductory 

 section. They will be found distinguished by inclosure in brackets. 



MARCH, 18TO. 



