i62 American Quarterly Microscopical Journal. 



On the Influence of Diffraction in Microscopic Vision. — 

 Frank Crisp. 



Address of the President. 



ZEITSCHRIFT FUR MIKROSKOPIE. 



October, 1878. 



Development and Present Condition of Microscopy in Ger- 

 many. — Dr. Edward Kaiser. — Concluding article of a series upon this 

 subject. An historical summary of the work of German investigators^ 

 containing copious references, which is of great value. 



On Preparation and Preservation of Microscopic Water- 

 Inhabitants. — For some time Duncker, of Bernau, has been selling a 

 fluid in which Infusoria are well preserved, but its composition is a 

 secret. The author has used a medium which he thinks may be the 

 same, at least it acts equally well. For preserving Infusoria, Rhizo- 

 poda, Flagellata, Ciliata, Chlorophyllacese, Desmidiacese, Acineta, 

 Daphnia, etc., the following process is followed : 



In the center of a lac-cell, not fully hardened, place the organism 

 in a few drops of water, apply the cover-glass, and then place a couple 

 of drops of Pyroligneous acid so that it will be drawn into the celL 

 Cement the cover down and the work is done. The objects may be 

 stained by such anilin colors as are soluble in water (the best are ani- 

 lin blue, or diamond fuchsin) by staining in the following solution : 



Anilin blue, i part, water, 200 parts, after filtering, Pyroligneous acid, 

 800 parts (all by weight). This stains the objects in a few hours, and 

 they may then be mounted in pure Pyroligneous acid. 



Study of Foreign Microscopes. — Dr. J. Pelletan. 



A New Cover-Glass Tester. — A simple device for measuring the 

 thickness of glass covers. 



On Collecting and Cleaning Diatomaceous Material. — C. 

 Janisch. — Silk gauze is useful to separate small from large forms, and 

 diatoms from foreign matters. 



JOURNAL DE MICROGRAPHIE. 



November, 1878. 



Micrography at the Exposition of 1878. — Dr. J. Pelletan. — A 

 review of the decisions of the jury on instruments of precision. 



In every respect the decisions do not appear to the author just. 

 Mr. Zentmayer's " Centennial " stand was worthy of the finest gold 

 medal, which he did not secure. 



List of Prizes at the Expositiqn. — A full list of prizes and 

 medals given for instruments of precision. Among the names familiar 

 to our readers we mention the following : 



M. Cailleett received a grand prize ; Brunner freres a grand medal ; 

 Dallmeyer, Dubosque, Nachet, Prazmowski, Ross, Chas. A. Spencer 



