Sees No. 6 Murray Street, New York 
Manufacturers of Balances and Weights of Precision for Chem- 
ists, Assayers, Jewelers, Druggists, and in general for every use 
where accuracy is required. 
April, 1871.—[tf.] 
-_R. FRIEDLANDER & SOHN, 
_——sBerlin (Germany), N.W., Carlstrasse 11 
_ Natural wae and Natural Science Booksellers 
Established 1827, 
ARE PUBLISHING SINCE 1879, EVERY si od eiahga 
k of the whole Literature of Natural History and the Exact = : 
catalogue in parts (« ial depart of s 
: ear oo ee pices number gratis on application. 
