12 ON SECTION CUTTING. 
together at their edges, so as to forma ribbon. To ensure this 
the razor should be placed at right angles to the direction of 
stroke, and the edges of the block of paraffin cut parallel to one 
another, and to the edge of the razor. If for any reason it is 
desirable to imbed the specimens in a paraffin too hard to form 
ribbons, the block should, before cutting, be coated with a 
layer of soft paraffin, by dipping it for a moment in a dish of 
melted soft paraftin. This outer coating should be left on the 
sides of the block parallel to the edge of the razor, but cut 
away from the sides at right angles to it. 
The razor should be used dry: and the sections, when cut, 
placed on slides painted, just before they are used, with a thin 
layer of a mixture of collodion and oil of cloves in equal parts. 
The slide is then heated by a water bath to a temperature not 
exceeding 55°—60° C., so as to melt the paraffin and evaporate 
the oil of cloves. The melted paraffin should then be washed 
off by turpentine, when the sections will remain fixed to the 
slide by the collodion, and may be mounted in balsam in the 
usual manner. 
Instead of the mixture of collodion and oil of cloves, a solution 
of shellac in absolute alcohol may be used: this should be 
spread over the slide in a thin layer by means of a glass rod 
and allowed to dry. Immediately before being used the slide 
should be brushed over with oil of cloves. 
