FUNDAMENTAL CONSIDERATIONS 
27 
ber on scale representing thickness in microns desired of sections and 
turn wheel of microtome.. It will be observed that the carrier moves 
up and down and with each downward movement slightly forward, 
causing the knife to cut s’ections which adhere in ribbons. 
Transfer the ribbons by means of a camel’s hair pencil or dissecting 
needle to a piece of dust free paper with the side downward which was 
next to the knife. The ribbons are now ready to be mounted on 
slides. 
The slides to be used should only be those which are devoid of 
grease or dirt of any kind particularly on the surface upon which 
the ribbons are to be mounted. A very good plan is to keep a number 
of slides intended for this purpose submerged in a saturated solution 
of potassium dichromate in concentrated sulphuric acid. These 
can be taken out as needed and thoroughly rinsed with water. 
With a clean cloth stretched over the forefinger vigorously rub 
one surface of each slide until perfectly dry and free of lint. Then 
place a small drop of Mayer’s albumin fixative on clean surface and 
rub over the surface. (The formula for Mayer’s Albumin Fixative 
is as follows: Egg white and Glycerin, equal parts, Carbolic acid 
1 or 2 drops. Mix thoroughly.) Now flood the surface with water 
and cut the ribbons into segments of the desired length and arrange 
in rows on slide, being careful to have the segments somewhat 
shorter than the length of the cover slip because of tendency of 
paraffine to stretch when warmed. Warm slide gently by holding 
high above a bunsen flame or flame of an alcohol lamp until ribbons 
stretch out in smooth fashion. Absorb superflous water from be¬ 
neath ribbons with blotting paper held to their edges and at same 
time push the sections into even rows. Then leave the sections to 
dry for several hours or over night. 
METHOD FOR THE STAINING AND MOUNTING OF MATERIAL IN 
PARAFFINE RIBBONS AFFIXED TO SLIDE 
1. Gently heat the dry slides with paraffine ribbons adhering to 
the fixative, high above the Bunsen flame (with the ribbon side up). 
2. Place the slide upright in a well of xylol or turpentine. The 
xylol or turpentine will dissolve the melted paraffine in a minute 
or two. 
