ZOOLOGY AND BOTANY3 MICROSCOPY, ETC. . 463 



small quantities ; Mr. Eichardson having found it for water = 1 • 3335 

 by this method, which is usually correct to two places of decimals. It 

 can also be used to determine if the lens is uniformly curved and 

 spherical. 



New Microscopical Journals. — Two new Journals have made 

 their appearance. The first is the quarterly ' Zeitschrift fiir wissen- 

 schaftliche Mikroskopie und fiir mikroskopische Technik,' published 

 at Brunswick, and edited by Drs. L. Dippel, M. Flesch, A. Wichmann, 

 and W. J. Behrens. It embraces " Microscopy " in its widest sense, 

 and includes original articles, abstracts and reviews, and a biblio- 

 graphy of microscopical literature. It may be recommended to all 

 microscopists who read German. The other is the bi-monthly 

 ' Microscopical Bulletin,' published by Queen and Co., of Philadelphia, 

 which, though unpretentious, gives useful information on micro- 

 scopical subjects. 



Bausch, E. — A new Condenser. [Fost.1 The Microscope, IV. (1884) pp. 105-6. 

 „ „ Eye-pieces and Objectives. 

 [General explanations.] The Microscope, IV. (1884) pp. 107-12. 



Bausch and Lomb Optical Co.'s Improved " Investigator " Stand. 



[Cf. I. (1881) p. 100. Mirror and substage now swing independently, 

 position of body-rack changed, &c.] 



Amer. Mon. Micr. Journ., V. (1884) p. 84 (1 fig.). 

 BoHN, C. — Ueber die Berichtigung des vereinfachten Ablese-Mikroskopes fiir 

 Theilungen. (On the rectification of the simplified reading Microscopes for 

 graduations. [Supra, p. 436.] 



Zeitschr. f. Instrumentenk,, IV. (1884) pp. 87-8. 

 Bond, G. M. — Standards of Length and their Subdivision. 



[Describes the Saxton Yard-dividing Comparator, the Rogers-Bond Universal 

 Comparator, and a Comparator made by the Ballon Manufacturing 

 Company for Professor Anthony.] 



Journ. Franklin Institute, CXVII. (1884) pp. 281-95, 357-67 (5 figs.). 



Bkadbuey, W. — The Achromatic Object-glass. XXXII.-V. 



Engl. Mech., XXXIX. (1884) pp. 93-4, 159-60, 246-7, 272 (6 figs.), 

 •' Calculus." — Polarizer for the Microscope. 

 [Simple contrivance to fit on tail-piece.] 



Engl. Mech., XXXIX. (1884) p. 215 (1 fig.). 

 CoNGDON, B. A. — Microscopy one hundred and fifty years ago. 

 [Notes on ' Baker on the Microscope,' 1740.] 



The Microscope, IV. (1884) pp. 74-6. 

 D., E. T. — Graphic Microscopy. 



IV. Pollen of Mallow. V. Peristome of Fumaria hi/grometrica. 



Sci.-Gossip, 1884, pp. 7.S-4 (1 pi.), 97-8 (1 pi.). 

 Davis, G. E. — [Leitz's] Oil-immersion Objectives. 



Micr. News, IV. (1884) pp. 131-2. 

 „ „ Evenings with the Microscope. I. 



[Measuring magnifying power of objectives and eye-pieces, and testing 

 corrections of objectives.] 



Micr. News, IV. (1884) pp. 132-5. 

 „ „ Microscopy. Sci. Monthly, I. (1883) p. 26. 



