ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 161 



Zenger's Mounting for Diatoms, to view them on both sides.— 

 Dr. C. V. Zenger writes us as follows : — " It is of the utmost impor- 

 tance for the study of diatoms and their structure, to view the pre- 

 parations from opposite sides, and I have found very useful a simple 

 and expeditious mode of obtaining a double-sided cell. 



I use two circular covers just fitting on the plane surface of the 

 Abbe condenser. After well rinsing with pure alcohol or benzine 

 and drying, a circular disk of tin-foil is cut of exactly the diameter of 

 the covers. A concentric hole is punched out, and the tin-foil ring 

 thus obtained glued to one of the covers. After drying over a small 

 gas-burner, the shallow cell thus formed is warmed and filled with a 

 solution of tolu balsam in benzine ; and the other cover with the 

 diatoms burned on its surface is placed on the cell, squeezing out 

 with the nail the superfluous imbedding liquid on blotting-paper, 

 so that it will immediately suck away the liquid pressed out. Wool 

 or cotton dipped in benzine or pure alcohol may be used to wipe the 

 borders and surface of the cell to clean it, turning it round on the 

 blotting-paper, so that the other side is equally cleaned. It is then 

 dried over a small gas-burner very cautiously to get rid of air-bubbles, 

 and to fasten the covers. Both covers having the same thickness 

 and diameter, there is no fear of separating them. In order not to 

 confound the different views, the tin-foil is painted with red lacquer 

 on one side, so that the particular side under the object-glass can be 

 readily distinguished. Immersion can be used on both sides, on that 

 turned to the condenser or to the object-glass, or both sides at once." 



Ady, J. E. — The Microscopic Study of Rocks. 1. 



[Includes methods of preparing.] Sci. Monthly, III. (1885) pp. 1-4. 



Almqvist, E. — Die besten Methodeu Bacterien rein zu cultiviren. (The best 

 Methods for the pure cultivation of Bacteria.) 

 [(1) Pasteur, (2) Koch, (3) in a moist chamber. The last for observations 

 on tlie development of an individual from spore to spore.] 



Bot. Centralbl., XIV. (1883) pp. 286-7. Also Hyguea, 1883. 

 Arnold, C— See Turntable. 

 B.Sc— See Turntable. 

 Baldwin, L. A. — Staining and Mounting Casts, &c. 



[Inquiry for satisfactory process and reply by E. Hitchcock.] 



Amer. Man. Micr. Journ., V. (1884) p. 240. 

 Barrett, J. W. — A new Method of Cutting Sections for Microscopical Ex- 

 amination. 

 [Describes the « Celloidin Method."— See Vol. IV. (1884) p. 822.] 



Journ. Anat. and Physiol., XIX. (1884) pp. 94-6. 

 Becke, F. — Ueber die Unterscheidung von Augit und Bronzit in Diinnschliflfen. 

 (On the Discrimination of Augite and Bronzite in thin Sections). \_Post^ 



Tschermah!s Mineralog. und Petroyr. Mitthlg., V. (1883) p. 527. 



Braun, M. — Die tbierisohen Parasiten des Menschen, nebst einer Anleitung zur 



praktischen Beschaftigung mit der Helmiuthologie fiir Studirende und 



Aerzte. (The Animal Parasites of Man, with instructions in practical 



Helminthology for Students and Physicians.) [Post.'] 



223 pp., 72 figs., 8vo, Wiirzburg, 1884. 

 Brown, G. D. — Mounting dry opaque objects without cover-glass. 



[His collection of Polyzoa is mostly so mounted. Objects are tlius better 

 seen by reflected light, there is no condensation of moisture on the cover- 

 glass, and no fungi.] 



Journ. of Microscopy, IV. (1885) p. 42. 

 Ser. 2.— Vol. V. ' M 



