INTRODUCTORY HISTOLOGICAL STUDY 
2 5 
Prepare a watch crystal or other small container by smearing 
its inner surface with glycerine. Pour into it enough melted par¬ 
affine to amply cover the piece of material which is to be imbedded. 
Transfer the material to this container by means of a slightly 
warmed section lifter or a strip of stiff paper. Before the par¬ 
affine begins to solidify, adjust the material to any desired posi¬ 
tion by means of a warmed instrument, and if more paraffine is 
needed it may be added. The material should not be in the least 
disturbed, however, after the paraffine has begun to solidify. 
Cool the paraffine rapidly by gently blowing across the surface 
and at the same time gradually lower the container into a dish of 
cold water, carrying it under the surface of the water as soon as 
the paraffine is hard enough to stand the pressure. Leave it under 
the water until the paraffine is thoroughly hardened. 
Sectioning. —The block of paraffine in which the material is 
imbedded should be shaved down to a rectilinear form a little 
larger than the imbedded mass, and should be securely fastened 
by means of melted paraffine upon a cork or other device for 
holding it, taking care to so orient it as to obtain sections in what¬ 
ever plane is desired. Adjust the block to the microtome with 
the edge of the knife parallel with two edges of the block in such a 
way that the knife will pass through the shorter dimension of the 
object. Cut sections of the desired thickness, about io or 15 
micra (a micron is .001 mm.), for ordinary study. 
Spreading Sections on Slide. —These sections, which must be 
handled with the greatest of care by means of forceps or a camePs- 
hair brush, should be placed upon the middle of a microscope slide, 
which has been previously smeared with albumen fixative, 1 thor¬ 
oughly rubbed in. 
The sections, if not wrinkled, may then be fastened to the slide 
by gently warming the preparation, holding the slide high above 
the alcohol flame, until the paraffine surrounding the section 
shows signs of being about to melt. 
If the sections are wrinkled, place a drop of water in contact 
with them before warming the slide. This drop will run under 
1 Albumen fixative may be conveniently prepared by mixing thoroughly equal 
parts of filtered white of egg and glycerine, and adding a little sodium salicylate 
or a few crystals of thymol as a preservative. 
