U. S. DEPARTMENT OF AGRICULTURE. 



DIVISION OF CHEMISTKY. 

 BULLETIN NO. 25. 



A POPULAR TREATISE 



ON THE 



EXTENT AND CHARACTER 



j 



J. M. RUSK, 



r 



8. 



PUBLISHED BY AUTHORITY OF THE SECRETARY 01' AGRICULTURE. 



WASHINGTON: 

 GOVERNMENT PRINTING OFFICE. 



1890. 



