"P van Rijckevorsel" wrote in message .. .
Gene Newcomb schreef
Just to elucidate on PvR's clamp, the classic technique is the use of
the pith from ...

+ + +
that would be Sambucus, elder
+ + +

It is sliced lengthwise and the material inserted into it. An
available substitute that should work on lichen thalli is a piece of
carrot. The little carrots sold in bags ought to work nicely.

+ + +
Or Styrofoam, in one of the denser grades
PvR

A microtome is an instrument your ingenuity might perhaps be able to
improvise. Movement of either blade or specimen (in elder-pith, etc)
is done by turning a screw, so you can get finer adjustment than the
unaided human hand could manage. At least one of the older books on
microscopy gave instructions for making a non-improvised durable one,
but I'm afraid I can't remember which, and I haven't got it any more.

Mike.