126 NATURALISTS’ ASSISTANT. 
It will be seen that in the above hardening processes the 
specimen was left in strong alcohol. ‘This fits it for the next 
step, which is to soak it for a while (say half an hour) in spirits 
of turpentine. While the specimen is soaking the paraffine 
should be melted in a water bath (or invits absence a sand 
bath may suffice), over a spirit lamp or gas jet. A small por- 
tion of the paraffine should always be allowed to remain un- 
melted as thus the remainder will not acquire too high a 
temperature. When melted a portion of the paraffine is 
poured into a paper tray covering the bottom to the depth of 
an inch, and just allowed to “set.’”’” The object is then re- 
moved from the turpentine, the superfluous spirit being re- 
moved by blotting paper, and next placed on the surface of 
the paraffine in the tray and completely covered by more of 
the melted paraffine, When cold it is ready for cutting. The 
object when placed in the tray should be in such a position 
that the sections may be cut in the desired plane, and note 
should be taken of its position, as after the paraffine becomes 
hard this is difficult to ascertain. 
In case the specimen to be embedded contains cavities, 
pains should be taken to fill these with paraffine. ‘The usual 
method of doing this is to transfer the object directly from 
the turpentine to a mixture of half turpentine and _ half par- 
affine which is kept just melted. After a few minutes’ immer- 
sion in this mixture it is transferred to the tray and the process 
completed as before. 
A convenient tray may be made from common writing paper 
by taking a piece of proper proportions to the object to be 
embedded, longer than wide and folded on the lines shown in 
