s soon as the slide
feels distinctly warm to the skin, the paraffin section will flatten out
and all wrinkles disappear.

(The slide with the section floating on it may be rested on the top of
the paraffin bath for two or three minutes, instead of warming over the
flame as here described.)

3. Cautiously tilt up the slide and blot off the excess of spirit with
blotting paper, leaving the section attached to the centre of the
slide.

4. Place the slide in a wire rack (Fig. 75), section downward, in the
"hot" incubator for twelve to twenty-four hours. At the end of this time
the section is firmly adherent to the glass, and is treated during the
subsequent steps as a "fixed" cover-glass film preparation.

NOTE.--If large, thick sections have to be manipulated, or
if time is of importance or acids are used during the
staining process, it is often advisable to add a trace of
Mayer's albumin to the alcohol before floating out the
section. If this substance is employed, a sojourn of twenty
minutes to half an hour in the "hot" incubator will be found
ample to ensure firm adhesion of the section to the slide.
The albuminous fluid is prepared as follows:

[Illustration: FIG. 75.--Section rack.]

~Mayer's Albumin.~--

Weigh out
Salicylate of soda 1 gramme
and dissolve in
Glycerine 50 c.c.
Add
White of egg 50 c.c.

Mix thoroughly by means of an egg whisk.

Filter into a clean bottle.

As an alternative method paint a thin layer of Schallibaum's
solution on the slide with a camel's hair pencil; lay the
section carefully on this film and heat gently to fix the
section.

_Schallibaum's solution_:

Clove oil 30 c.c.
Collodion 10 c.c.

Keep in a dark blue bottle in a cool place.

~Staining Paraffin Sections.~--

1. Warm paraffin section over the Bunsen flame to soften (_but not to
melt_) the paraffin, then dissolve out the wax with xylol poured on from
a drop bottle.

2. Remove xylol by flushing the section with alcohol.

3. If the tissue was originally "fixed" in a corrosive sublimate
solution, the section must now be treated with Lugol's iodine solution
for two minutes and subsequently immersed in 90 per cent. alcohol to
remove all traces of yellow staining.

4. Wash in water.

5. Stain deeply, if using a single stain, as the subsequent processes
d