89 



Verhandlungen der Russ. Kais. Mineralogischen Gesellschaft zu St. Peters- 

 burg. Jahrgang, 1857-8. 



Silliman's American Journal of Science and Art. No. 81, for May, 1859.. 

 Received in Exchange. 



Annals and Magazine of Natural History. Nos. 15, 16, and 17. London. 

 1859. From the Courtis Fund. 



Encyclopsedia Britannica. Vol. 17. 



Life of Fred. Wm. Steuben. By F. Kapp. With introduction by Geo. Ban- 

 croft. 8vo. New York. 1859. 



^Memoir of Theophilus Parsons, Chief Justice of Supreme Judicial Court of 

 Massachusetts. By his Son, Theophilus Parsons. 8vo. 1. 1859. Dejjosiled by 

 the RepMican Institution. 



July 6, 1859. 

 Dr. C. T. Jackson, Vice-President, in the Chair. 

 Mr. Stodder read the following paper : — 



ON COLLECTING, PREPARING, AND MOUNTING DIATOMACE^ 



FOR THE MICROSCOPE. 



BY ARTHUR M. EDWARDS, NEW YORK. 



Although most of the published treatises on the microscope 

 profess to give thorough directions for mounting objects in such a 

 manner as to preserve them for almost any length of time and 

 exhibit their characteristics, very few of them present any concise 

 descriptions of the best methods of collecting or mounting Diato- 

 macete. In general they treat solely of the fossil, or semi-fossil, 

 species, and even such directions as relate to these are meagre 

 and unsatisfactory for the most part, and, where they amount to 

 specific and special directions, are copied from other books, so 

 that any faults that may have been in the original are repeated. 

 To mount Diatomaceee for the purpose of sale is one thing, and to 

 prepare and mount them so as to exhibit the natural characters 

 for the purpose of study is another. The latter can only be 

 attained after considerable practice ; and to do it properly a cer- 

 tain knowledge of their natural history is necessary. 



The Diatomaceae should always be mounted for a special pur- 



