ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
267 
I, therefore, would advise every practical and expert microscopist, 
especially microscopists that are not artists in drawing, sketching, and 
in the art of producing microscopic illustrations, to make use of the 
grapho-prism. Especially so would I advise students of practical 
histology, physiology, pathology, pathological anatomy, bacteriology, 
embryology, and pharmacology to use the grapho-prism hand in hand 
with the Microscope.” 
A new Mechanical Stage. — The following is the text of the remarks 
made by Mr. H. Bernard when exhibiting his new stage at our meeting 
on December lGtli, 1891 : — 
The disadvantages of the mechanical stages hitherto in use in the 
microscopical world are too well known to need mention here. It is 
enough to say that they fail one exactly when they are most needed, 
viz. in the systematic study of large objects, such as series of sections, 
culture-plates, zoophyte-troughs, &c. 
The principle of the new stage is such that it is capable of adaptation 
to almost all the requirements of the microscopist ; the mechanism is 
intended to imitate the movements of the fingers as they shift the object 
about the stage. A 
study of the figures * 
will make my meaning 
clear. 
A plate a (fig. 31) 
slides in and out under 
the fixed stage of the 
Microscope-stand. A 
U-shaped piece is cut 
out of its inner end, so 
that it in no way inter- 
feres with the con- 
denser and substage 
apparatus. This whole 
plate is worked by a 
double rack, one on 
each side of the plate, 
and the pinion 1. The plate is made to slide completely out, but for the 
mechanical (transverse) movement of slides it has a range of about 7 cm., 
which is, as far as I know, more than twice the range of any other me- 
chanical table. When driven quite home, a projects about 2.^ cm. from 
the side of the stage, so that it is not much in the way, and may be left 
in its place when the mechanical movement is not required. 
The movement to and from the observer is obtained by means of the 
piece b which slides backwards and forwards across the end of a. It 
has a screw movement 2. In the example figured and described b has a 
range of about 3^ cm. But it is clear that this could be largely increased 
by widening the end of n. In the present case, in order to obtain greater 
range, a device is resorted to which will be described below. 
Having thus got a mechanical movement of 7 by 3^ cm. at the sides 
* The engravings are from photographs kindly taken for me by Mr. C. J. Robinson, 
of 3, The Broadway, Streatham, S.W. 
Fig. 31. 
m. 
