ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
103 
MICROSCOPY. 
a. Instruments, Accessories, &c * 
(1) Stands. 
Leitz’s Microscope.f — The large Microscope of Leitz, No. I a, shown 
in fig. 1 on the next page, can be inclined at any angle ; the coarse- 
adjustment is by rack and pinion, the fine by micrometer screw with 
divided head ; the draw-tube is provided with a millimetre scale ; the 
Abbe condenser, with iris diaphragm, can be raised and lowered by rack 
and pinion. The ordinary cylinder diaphragm is readily adjusted by 
simply turning aside the iris diaphragm and slipping out the condenser. 
The instrument is provided with a triple nose-piece. 
Leitz’s New Microscope Stand.f — Mr. E. M. Nelson points out that 
Leitz’s new stand is a nearer approach to the “ English ” model than 
any Continental instrument hitherto constructed. Instead of the heavy 
horse-shoe foot, there is a bent claw with a spread of 5 by 6 inches. Mr. 
Nelson’s horse-shoe stage has been adopted, but the spring clips on the 
sliding bar ought to be removed. 
An altogether novel procedure in Microscope construction is to be 
found in the substage rackwork ; the rack is not in the groove, but on 
one side of it ; there is no U-shaped groove at all, but a flat piece of 
steel which is pressed downwards by a spring ; this is tightened up by 
a screw. Experience alone can decide whether, as seems probable, we 
have here a very simple and smooth form of slide. 
Microscope for Measurement of Growth of Plants.§ — Herr J. 
Wiesner describes the apparatus, constructed for him by C. Reichert 
of 'Vienna, which he made use of in his experiments on the influence of 
light on the increase in length of the organs of plants. 
The instrument consists of two separable parts, the stand and the 
body-tube of the Microscope. The stand is composed of a horse -shoe 
base and a vertical column, which serves to support the body-tube of the 
Microscope in the horizontal position. 
The column has a height of about 119 mm. and can be lengthened 
by 70 mm. At the back of the movable part of the column is a divided 
scale, 60 mm. long, which is read off against the vernier attached to tho 
fixed part of the column. The raising of the column, and with it the 
Microscope, is effected in the usual way by rack and pinion. 
The Microscope is connected with the stand by a pin, and is fixed 
by a screw. The body-tube can be displaced in the horizontal direction 
by rack and pinion for the purpose of adjusting the object. The whole 
Microscope can also turn in the horizontal plane about the pin, men- 
tioned above, on the loosening of a screw. 
As objective the Reichert system la was used. With a tube-length 
* This subdivision contains (1) Stands ; (2) Eye-pieces and Objectives ; (3) Illu- 
minating and other Apparatus; (4) Photomicrography; (5) Microscopical Optics 
and Manipulation; (6) Miscellaneous. 
f Catalogue No. 34 of Microscopes and Accessory Apparatus. Ernst Leitz, 
Wetzlar, 1892, p. 19. 
\ Journ. Quekett Micr. Club, v. (1893) pp. 309-11 (3 figs.). 
§ Zeitschr. f. wiss. Mikr., x. (1893) pp. 145-8 (1 fig.). 
