206 The Sledge Microtome. . [ April, 
the distance the object is moved up the inclined platform be- 
tween the first and second cuts. 
Figure 26 represents the microtome as seen from above, one half 
the natural size. A, which is shaded, represents the base; BB 
is the top of the partition, and is marked off into millimeters, 
though only the centimeters are represented in the cut; on the 
right is the horizontal platform C, while the sledge (S7) is rep- 
resented lying on it; the sledge is provided with a screw pin 
(P) for fastening the knife, the handle of which is provided with 
a slot into which the pin may be slipped; the knife (An) is 
placed obliquely, as seen in the figure, so as to project over the 
other side of the partition. The sledge is made so high that the 
knife lies above the top of the partition. On the left-hand side 
of the partition is the inclined platform D, carrying the sledge or 
object holder OH. This carries a clamp shaped very much like 
one of the patent clothes-pins now so much in vogue for hanging 
up maps and diagrams. The object to be cut must be imbedded 
in paraffine or soap; it is then placed between the front arms of 
the clamp, where it is held tightly by the action of a spiral spring 
between the hind arms (compare Figure 26), so arranged as to 
press the front arms together. 
The object holder must be slid down and the knife sledge 
pushed forward, and the first cut may be made by pulling the 
knife back. After making the cut the object is again shoved up 
the inclined platform a little way ; the exact distance may be de- 
termined by means of the scale on the top of the partition BB . 
The inclination of the platform is such that the slice cut off is m 
thickness one twentieth of the distance which the object has been 
shoved forward, that is, the rise is one in twenty, so that if the 
object be moved forward 1 m.m, the section will be 3y m.m., and 
so on. 
No sooner has one section been cut off than another may be 
made, which will be exactly parallel to the first. In this way a 
long object can be cut into very thin sections, all equally good, 
and exhibiting every part of the body cut. Now, suppose asma 
worm to be cut in this way into transverse sections, we could ex- 
amine first the head and then the successive portions of the body. 
I have frequently made long series of such sections, and ons 
found them to afford a surer means of studying the anatomy vg 
minute opaque animals than any other I know of, for m this way 
every portion of the animal may be subjected to minute exami- 
nation, and, further, the sections once made and mounted they 
