SECTION CUTTING. 195 
rapidly this takes place the better will the block cut. 
When the paraffin mass has hardened completely 
throughout it is trimmed into shape, taking care 
that the edges of the surface which is to be cut are 
accurately parallel. 
Fic. 32.—L-shaped moulds for embedding in paraffin. 
CUTTING THE SECTIONS. 
For cutting sections in paraffin no microtome can 
be compared with the Cambridge Rocker, but very 
excellent results can be obtained by the use of the 
Cathcart microtome already mentioned. The paraffin 
block containing the piece of tissue is mounted on 
the freezing plate of the microtome (which must be 
heated and the lower surface of the block pressed 
upon it) and the sections cut in the manner -de- 
scribed; a very sharp knife is essential and the 
stroke must be quicker and sharper than is the case 
when frozen sections are being cut. In another form of 
the microtome a special inner tube is provided for 
cutting sections by the paraffin process. The blocks are 
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