ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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of Iris low-priced substage will be quite unsteady enough in itself 
without the addition of a pivoting motion. 
As to the pivoting system being recommended by Messrs. Watson’s 
medical patron at “ Modern Athens,” that fact suggests to me only the 
probability that the recommendation is based on very limited experience 
of high-class work ; whilst their own approval of it, according to the 
tone of their letter, seems largely due to commercial reasons which are 
not in my province to discuss. 
I condemn the system on its merits as totally unfit to be combined 
with a mechanical substage. I see in its application only the evasion of 
the recognized good and durable methods of attaching the substage to 
the Microscope, which are adopted wherever such matters have been 
seriously aimed at. 
We have had, in all conscience, enough, with over-measure, of 
inferior constructions of students’ Microscopes. Let us now aim at 
something altogether better. — Mioroscopist.” 
An Illuminating Cell.* — Mr. F. O. Jacobs describes a cell made of 
any white metal that will take a bright polish, and shaped so as to 
reflect the light it receives from the mirror to the object, which is 
mounted on an opaque ground. The cell completely covers the object 
but is perforated by an opening of the same size as the ground on which 
the object is mounted, which should be just large enough to inclose the 
field. The arrangement is completed with a small cover-glass. The 
advantage of this cell is, that it saves time in adjusting the light and 
condensing lens, the same lighting being used as with a transparent 
object. 
Bulloch’s Mechanical Stage with Vertical Pinions. — In the various 
constructions of this form of stage since its comparatively recent intro- 
Fig. 90- 
duction by the late R. B. Tolies, the mechanism has generally been 
defective in the matter of durability; in the endeavours to secure 
extreme thinness of the support for the slide, the attachment of the 
* The Microscope, x. (1890) p. 281. 
