THE MICR OSCOPICAL JOURNAL ADVERTISER. vii 



Large First-Class Microscope For Sale. 



Zentiuayer's centennial stand, 3 eyepieces, rotating and reversable mechanical stage. 



Made specially to order $300.00 



Walnut case with lock, key and handle 10.00 



Bull's eye Condenser 10.00 



2 J and i inch solid eyepieces at 7.50 22.50 



Beck's first class 4-inch objective, angular aperture 9° 12.00 



" " " 2 " " " " 18° 20.00 



H. R. Spencer & Go's first-class 1 inch objective of 40° 40.00 



'* " " " " " " 4 " Homogeneous Immersion objective B. A. 110° 65.00 



" " " " " " " 1-10 inch " " '" " " 125° 80.00 



Amplifier 8.00 



Beck's triple nose-piece 15.00 



Webster's Achromatic Condenser 17.50 



Mechanical finger 6.00 



$605.00 

 But little used, and as good as new. Will be sold for $400 to close an estate. 



Address : James H. Logan , 



Perrysyille Ave. , Allegheny, P a. 



AGE PRINTING COMPANY^ 



All kinds of scientific matter, books, pamphlets, cards, labels, 

 envelopes, letter heads, etc., printed and forwarded by mail or 

 express free of charge for delivery. Prices reasonable ; satisfaction 

 guarantied. 



Inventive Age Building, 



Washington, D. C. 



DESMIDS OF THE UNITED STATES, 



and list of American Pediastrums, with fourteen hundred illustra- 

 tions, on sixty-four colored plates. 



The work consists of 246 printed pages, including a carefully arranged index ; a brief 

 account of Algae in general ; a fuller one of Desmids in particular — directions how to find' 

 coUect, preserve and examine them ; a minute description of each of the 600 species and 

 vareties named in the index, and a descriptive catalogue to every plate of the plants illus- 

 trated thereon. A copy bound in cloth, carefully packed, and mailed or sent by Express 

 on receipt of the price, $6.50. 



Send all orders and remittances to, 



HAETLEY C. WOLLE, 



Bethlehem, Pennsylvania, U, S. A. 

 B^^There may be had also. Fresh-water Algae of the United States, $10.00 ; and Diato- 

 maceae of North America, price $6. 00. 



MODERN MICROSCOPY. 



Part I. — The Microscope and Instructions for its use. 

 Part II. — Microscopic Objects : How prepared and mounted. 



By Cross and Cole. 

 LARG^ OCTAVO, 104 PAGES, 30 FIGURES ; PRICE $1.25, POSTPAID. 



Address, Microcsopicai< Publishing Company, 

 ti Washington, D .C, 



