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SUMMARY OF CURRENT RESEARCHES RELATING TO 
greater rapidity. An air-tight chamber should be filled with chloroform ; 
a very wide-mouthed bottle will answer. After the mass is thoroughly 
hardened, which requires about twenty-four hours, it is removed, the 
paper cut from the sides, and transferred to 70 per cent, alcohol for a 
few hours. 
It is now ready to fix for sectioning. Blocks are trimmed to fit the 
clamp of the microtome. Solution No. 3 is poured over the block ; into 
this the celloidin block is pressed, after dipping the under surface in 
solution No. 1. Place in chloroform until hardened. 
Reconstruction points are often very desirable. For this purpose 
the ordinary metallic imbedding box made of two L-shaped pieces, 
held in place by overlapping strips, is used. The ends and sides are 
perforated in as many places as desired by a very small drill. The holes 
should be so drilled that the silk threads which are drawn through run 
parallel. 
After being drawn tightly they are cemented to the sides of the box 
by a drop of celloidin. Five or six cm. of the thread should be left 
hanging. The bottom of the box is made by fitting in a piece of heavy 
blotting-paper. The object is placed upon the threads in the desired 
position, and the imbedding mass poured in. As soon as hardened, the 
celloidin holding the threads is dissolved by a drop of ether. The loose 
ends are soaked in solution No. 2, which has been thickened by the 
addition of lampblack. The threads are then drawn through, leaving 
the lampblack adhering to the celloidin, thereby forming excellent 
reconstruction points. 
For small objects, where reconstruction points are not needed, the 
following method may be advantageously employed. The heads are 
clipped from fine insect pins, which are then placed in handles in such a 
way that they may be easily removed. On these pins the objects are 
oriented in the desired position ; the pins are then removed from the 
handles and fixed in a cork previously perforated by a somewhat larger 
pin. As fast as the pins carrying the object are inserted, the cork is 
replaced in the tube, which is filled with alcohol. A half-dozen fish 
or amphibian ova may be oriented on the same cork. If desirable to 
draw the objects in situ a piece of lead may be pinned to the cork, 
and the whole immersed in a small beaker of alcohol. The corks carrying 
the oriented objects are transferred successively to tubes containing the 
different solutions. When ready for final imbedding, a piece of porous 
paper is wrapped about the tubes and cork, and pinned. The cork 
is now removed, allowing the imbedding solution to fill the paper 
tube thus formed. A lead is fastened to the cork, and the whole 
placed in chloroform until hardened, after which the paper is cut 
from the mass and the pins drawn through the cork, when it is ready 
for sectioning. This method offers many advantages, in that several 
objects may be cut at the same time, drawings may be made after 
orientation, the objects are transferred from one solution to another 
more rapidly, &c. 
In cutting, care should be taken that the knife is placed as 
obliquely as possible and kept constantly wet with 70 per cent, 
alcohol. For this purpose an ordinary pipette provided with a large 
rubber bulb is used. As fast as cut the sections are drawn back on 
