ACKNOWLEDGEMENTS. 



THE Author acknowledges with pleasure, the valuable assist- 

 ance of several scientific and practical gentlemen, to whose 

 names he is permitted to refer viz: 



CHESTER DEWEY, M. D., Professor Chemistry, Geology, &c- 

 JOHN J. THOMAS, Esq. 



L. WlTHEREL, A. M. 



P. BARRY, Esq. 

 L. B. LANGWORTHY, Esq. 

 AARON ERICKSON, Esq. 

 D. D. T. MOORE, Esq. 



1C., GOODSELL, Esq. 



Several of the above named gentlemen have examined por- 

 tions of the manuscript of this book, and made such sugges- 

 tions and corrections as they thought necessary. 



They should not, however, be held responsible for any state- 

 ment which may appear to be erroneous, or for the selection* 

 and arrangement of the topics discussed. M.. M. E. 



