47 
is taken out of the cedar-wood oil and the excess wiped 
off in order to prevent the oil softening the paraffin. 
2. Place in a dish of melted paraffin for half 
an hour, more or less according to the size of the tissue. 
(If on removing and allowing the block to cool a cut 
made with a razor through the tissue looks quite 
uniform, it is a sign that the paraffin has penetrated 
properly). 
3. Arrange two brass blocks (L pieces) on an 
ordinary slide so as to form a trough of the required 
dimensions. Melt some paraffin in a dish and fill up 
the trough to the top. Now transfer the tissue with 
a warmed forceps to the trough and arrange as 
required. (As soon as the surface becomes opaque 
and semi-solid, the position of the object, if necessary, 
may be marked by scratching with a needle on the 
paraffin.) 
4. When the surface is solid, but not before, 
cool under a tap of water. 
5. Trim the block by cutting away successive 
slices. Take care that the sides are parallel. (Block 
trimmers are very useful where continuous series of 
sections are to be cut.) 
6. Put some paraffin on the block holder, warm 
in flame and now press on the paraffin block firmly 
until it adheres. Melt bits of paraffin around the base 
with a hot knife to give it further support. 
Treatment of Sections. —1. Place a trace (pin-head 
size) of egg albumen and glycerine on a slide and rub 
it carefully over with the finger (free from grease). 
2. Just cover the slide with water from a pipette. 
3. Lift a section (or ribbon if required) from the 
microtome with a strip of note paper. Avoid touching 
the knife. Now with the needle carefully draw the 
ribbon on to the water and repeat the operation until 
