TO 



DR. SILAS H. DOUGLASS; 



PROFESSOR OF CHEMISTRY, GEOLOGY, MINERALOGY, &C. y IN THE 



UNIVERSITY OF MICHIGAN; 

 TO WHOSE EXERTIONS AND ENERGY, TUB 



ESTABLISHMENT OF AGRICULTURAL LECTURES 



IN THAT INSTITUTION, 



IS, 



TO A GREAT EXTENT, DUE. 



AND WHO, FROM AN EARLY DAY, HAS EARNESTLY 



AND PERSEVERINGLY LABORED IN THE CAUSE OP SCIENCE I 



THIS STATE . 



THIS VOLUME 



IS DEDICATED BY HIS MOST SINCERE AKD 

 OBLIGED FRIEND 



THE AUTHOR, 



86197 



