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W. EMIL BOECKER, 

 MANUFACTURINGS OPTICIAN, 



WETZLAR, GERMANY, 



SENDS GRATIS HIS CATALOGUE 



OP MICROSCOPES, OBJECTIVES, MICROTOMES, AND APPARATUS 

 FOR SCIENTIFIC RESEARCH. 



Heinr. Boecker's Microscopical Institute, at Wetzlar, G-ermany, 



SUPPLIES 



MICROSCOPICAL PREPARATIONS 



In all branches of Natural History. A Large Selection of Injections, Stained Preparations, Insects, Crustacea, 

 Ento*>a, and Lower Animals; "Vegetable Anatomy, "Woods, Articles of Food, Alga*, Mosses, Fungi, Diatoms, 

 and Sections of Rocks and Fossils. Instruments and Appliances for Mounting, &c. Sciopticon, with addi- 

 ti«u for using microscopic objectives. Glass Photograms. 



Catalogue No. IX., Gratis and Post-free. 



Just Published, price Is. l\d. post-free, Part 3. 



THE JOURNAL OF THE POSTAL MICROSCOPICAL SOCIETY. 



CONTENTS. 



On the Embryology of the Podophthalmata, or Stalk-eyed Crustacea — The Adul- 

 teration of Coffee and the Microscope {Plate) — A New Growing-Slide (fflus.) — Spiders; 

 their Structure and Habits. Part 2 (Plate) — TJnpressed Mounting for the Microscope 

 — Aquaria for Microscopic Life — How to Prepare Foraminifera (Illus.) — An Hour at 

 the Microscope with Mr. Tuffen West (2 Plates) — Selections from the Society's Note- 

 Books {Plate) — Reviews — Correspondence (Illus.) — Notices to Correspondents, &c, &c. 



W. P. COLLINS, 158, Great Portland Street, London, W. 



THE " SOCIETY " STANDARD SCREW. 



The Council have made arrangements for a further supply of Gauges 

 and Screw-tools for the " Society " Standard Screw for Objectives. 



The price of the set (consisting of Gauge and pair of Screw-tools) is 

 128. Gd. (post free 12s. 10d.). Applications for sets should be made to the 

 Assistant-Secretary. 



For an explanation of the intended use of the gauge, see Journal of the 

 Society, I. (1881) pp. 548-9. 



ADVERTISEMENTS FOR THE JOURNAL. 



Mr. Charles Blkncowe, of 75, Chancery Lane, W.C., is the authorized 

 Agent and Collector for Advertising Accounts on behalf of the Society. 



