Bulletin No. 228 
Series I D ' Pfctr °g ra P^y anc[ Mineralogy, 26 
\ E, Chemistry and Physics, 40' 
DEPARTMENT Of THE INTERIOR 
UNITED STATES GEOLOGICAL SURVEY 
CHARLES D. WALCOTT, Director 
ANALYSES OF ROOKS 
FROM THE 
LABORATORY OF TEE UNITED STATES GEOLOGICAL SURVEY 
1880 to 1903 
TABULATED BY 
F. W. CLARKE, Chief Chemist 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1904 
