122 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
to the Degroot or Reinhold-Giltay microtomes, the author has adapted 
some subsidiary apparatus for facilitating the cutting of ribbon sections. 
The first of these is an arrangement for warming the knife. This con- 
sists of a kettle, heated by a spirit-lamp, which is placed on the right- 
hand side of the microtome. To the spout is connected a long rubber 
tube, passing along close to the back of the knife, its other end dropping 
into a vessel on the left of the microtome. The steam passing through 
the tube is found to impart sufficient warmth to the knife to prevent 
the sections curling, and also to render cutting more easy. The knife is 
placed at such an angle that the sections do not touch the blade, but are 
passed on to the ribbon frame. By a simple device the microtome is 
worked with a treadle, thus leaving both hands free for manipulation. 
The sections, which have been received on long strips of thin parch- 
ment paper, are then immersed in 70 per cent, spirit, preparatory to 
being stretched. During this process the sections not unfrequently get 
lifted by the development of air-bubbles underneath, and to get rid of 
these the author uses a special apparatus (fig. 23). As will be seen it 
is a pan having a plate on either side, that on the right 36 cm. 
long, being divided up by wire partitions 0*5 cm. thick and 4 cm. 
Fig. 23. 
apart. The pan, filled with 70 per cent, spirit, is" 6 cm. high and 
its bottom 10 cm. x 10 cm. The right side is vertical, the left slopes. 
The plate on the left has a leg inside the trough parallel to the oblique 
side, and can therefore be moved to and fro. To this leg is soldered a 
wire at such a distance that it is about 0 • 5 cm. below the level of the 
fluid (see fig. 23). On the right side is another wire parallel to and 
0*5 cm. above the bottom of the trough. This is also movable to and 
fro by means of a screw. By passing the strips of paper, which have 
been placed on the long plate, underneath the two wires and through 
the fluid, a perfectly smooth surface is obtained. If necessary they can, 
when they are lying flat on the left plate, be cut up into strips. The 
strips are then passed rapidly over a roller placed in a vessel filled with 
water heated to 60°-70° C. (fig. 24). The apparatus is merely a copper 
tank in which a glass or porcelain roller is placed. The measurements 
of the tank are 12 x 5 X 5 cm., and the roller projects 0*5 cm. above 
the top. By passing the bands to and fro as indicated in the illustra- 
tion, the sections are damp-stretched. 
As a solvent to the paraffin the author expresses his preference for 
benzin, and then goes on to consider how the section should be stuck. 
Two great divisions are made : (1) where the sections are to be examined 
unstained or where the object has been stained in toto. (2) Where the 
