SECTION CUTTING. 129 
When about to begin cutting the sections, the paraffine 
mass should be removed from the tray and trimmed to a con- 
venient size, leaving more material behind the object than in 
front of it. Slices should then be carefully taken from above 
the object until it is reached and then even greater care should 
be taken. In case a mass of tissue is being cut it should be 
pared down until a good surface is reached, the slices taken 
off being rejected. Whenan embryo is being cut every slice, 
whether perfect or not, should be preserved. Always, when 
cutting sections from paraffine embeddings, the up- 
per surface of the razor should be flooded with 
strong alcohol; when soap is used water replaces 
the alcohol and with glycerine jelly glycerine is. 
useful. The object of this is to float the object up 
and prevent its sticking to the razor and thus be- 
coming torn. It is convenient to have a shallow 
tank before the worker filled with alcohol or water, 
into which the razor with the section is dipped, the 
section being floated off and the razor wetted for F'- 39 
the next section at the same time. When a sufficient number 
of sections have been cut from a paraffine embedding, the 
embedded material may be sealed up by placing a drop or 
two of melted paraffine on the cut end and the whole then 
labelled and put aside for future sections. A specimen thus 
embedded will keep for months without injury and may be 
cut from at any time. 
After cutting, the sections are to be freed from their em- 
bedding material. In the case of paraffine this is accom- 
plished by immersion in turpentine. When soap, or gum, or 
9 
