16 ( 
AMERICAN JOURNAL 
. SCIENCE AND ARTS. 
i 
CONDUCTED BY 
Proressors B. SILLIMAN, B.-SILLIMAN, Jr., 
AND , 
JAMES D. DANA. 
AIDED 
* 
IN THE DEPARTMENTS OF CHEMISTRY AND PHYSICS 
BY 
Dr. WOLCOTT GIBBS. 
SECOND SERIES. 
VOL; Xkhe_MAY, 186 
WITH TWO PLATES. 
