ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
243 
£3) Illuminating 1 and other Apparatus. 
Apparatus for Electrolysis under the Microscope.* — Dr. W. Kaiser 
describes the apparatus which he uses for electrolysis and for electro- 
physiological experiments with infusoria and bacteria under the Micro- 
scope. 
The apparatus is represented in section and plan in figs. 46 and 47. 
In fig. 46, E F G H is an ordinary slide, on which is cemented by Canada 
Fig. 46. 
balsam the conical glass block bl. This block is pierced by six holes,, 
of which only the two middle ones at hr are visible in fig. 46. Under- 
neath, where the block is cylindrical, these borings, which are parallel 
in pairs, meet at an obtuse angle the borings /3 /?. The ends of the six 
borings on the upper face of the block are seen in fig. 47, at ab cdef. 
Through these openings are drawn the three platinum wires which serve 
as electrodes in the apparatus. Only the upper parts of the wires between 
a and b, c and d , e and /, are left free. These parts, a b, c d, e /, of the 
wires are parallel to each other, and about 5 mm. long. The outer 
wires a b and e f are 0 • 2 mm. thick, the middle wire c d is 0 • 1 mm. thick, 
and 1 mm. distant from the other two. In fig. 46 the further course of 
the wire c d is shown as a white line on a black ground. At c and d l 
and at X and X L the wire is bent at an obtuse angle. On the right it 
passes from X l to p 2 , but on the left it ends at y. The pieces X lf p 2 and 
X y are imbedded in black sealing-wax, or rather are between two glass 
plates cemented together by sealing-wax. For on the slide E F G H 
(fig. 46) is cemented a thick object-holder A B C D conically bored 
through in the middle, so as to fit over the block bl and leave a groove o 
round it, as seen in fig. 47. The glass block bl (fig. 46) is about 0 * 1 mm. 
lower than the thickness of the plate A B C D, so that when a cover- 
glass S— is placed over the aperture o-o 1} there is room for a drop of 
liquid t-t 1 (fig. 46) between the cover-glass and the upper surface of the 
glass block on which are the platinum wires. Fig. 47 shows the appa- 
ratus as seen from above, and explains how the platinum wires are con- 
nected with the terminals of the battery. The middle wire c d which 
forms the cathode has its branch p 2 on the right soldered to the strip- 
of copper foil Aq, while on the left the ends p and of the outer wires 
a b and e/, which together form the anode, are soldered to the copper 
strip Jc. The copper strips are firmly held by the cement between the 
plates, and project about a decimetre beyond them to the clamping- 
screws Jc l and Jc to which the wires from the battery are attached. 
A drop of the liquid to be examined is brought on to a cover-glass S-S L 
* Sitzungsber. Akad. Wiss. Wien, civ. iii. (1895). 
