ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



91 



Scheffer, W. — Das Mikroskop, seine Optik, Geschichte und Anwendung. 



Leipzig (Teubner), 8vo, 114 pp. and 66 figs, 

 Thon. — Ein nenes Trichinenmikroskop. 



Deutsche Thierarztl. Wochenschr., 1902, No. 8, p. 74. 

 Wolffhugel, K. — Ein nenes Trichinenmikroskop. 



Zeit.f. Fleisch- u. Milchhyg., 1901-2, H. 3, p. 78. 



(2) Eye-pieces and Objectives. 



Barbour's Pocket Magnifier.* — This little instrument (D, fig. 9) is 



and is made by Messrs. 



primarily intended for the field geologist, 

 Bauscb and Lomb. The inventor's idea was 

 to design a pocket magnifier which should 

 fit in the vest pocket like a small flat watch, 

 free from angles and corners. It contains 

 Hastings; triplets of 5, 10, and 20 diameters, 

 together with a compass. If desired, the 

 compass could be omitted, and the size thereby 

 reduced. 



Bourguet's New Index Ocular.t — This 

 ocular (fig. 10) contains a pointer, adjustable 

 from outside, by means of whose point every Fig. 10. 



spot of the field of view can be indicated. 



It is especially adapted for giving students of histological and bacterio- 

 logical classes definite information about anv part of the microscopic 

 field.? 



Franzbsische Mikroskope. 



[An account of progress recently made by French opticians in the manu- 

 facture of objectives.] 



Central. Ztg.f. Opt.u. Mech., XXIII. (May 1902) p. 98. 



Hartwich, C. — Ueber ein paar Mikroskopoculare mit Messvorrichtung. 



Centralztg. f. Opt. u. Mech., XXIII. (1902) p. 11. 



Malassez, L. — Sur les oculaires a glace micrometrique et a usages multiples. 



Arch. d'Anat. Microsc, IV., fasc. 2, 3 (1901) p. 219. 



McGregor-Robertson, J.— Ehrlich's Eye-piece for the Differential Count of 

 Eed and White Corpuscles in Stained Films. 



Glasgow Med. Journ., LV. (1901), No. 5, p. 339. 



Sohaffner, J. H. — Oculars for General Laboratory Work. 



Journ. App. Micr., V. (1902) p. 1646. 



(3) Illuminating and other Apparatus. 



Watson and Sons' Macro-Illuminator .§ — This is a single achromatic 

 combination of 1\ in. clear aperture and 2 in. focus. It excels in pro- 

 ducing a brilliant and uniform illumination of large objects under low 

 powers. The lens is mounted to fit into the substage, close to the 

 object, so as to focus the image of the source of light on the objective. 

 Objects up to fully 1 in. in diameter may be thus illuminated with 

 absolute uniformity. It is extremely valuable for photography with the 

 holostigmat and planar types of lenses. 



* Loc. cit. 



t Zeitschr. angew. Mikr., viii. (1902) p. 33 (1 fig.). 



% This ocular is a reinvention of Quekett's indicator eye-piece (1848). 



§ W. Watson & Sons' Catalogue. 1902-3, p. 99. 



