Hi
You need to melt down the block and reverse-process it ,Gayle Callis 
describes this  in her chapter on bone in the 5th edition of Theory and 
practice if Histological Techniques.
Take the bone back through a couple of changes of xylene a few hours in 
each and then through two changes of absolute alcohol a few hours in each 
to remove any residual water. Most problems associated with the processing 
of bone are caused by inadequate dehydration. We leave our bone in 1% 
fabric softener made up in tap water after decalcification and prior to 
processing and it processes using normally with our other tissue on an 
overnight schedule.

Gerard Spoelstra
Medical Scientist
Veterinary Histology
Murdoch University

  At 04:42 PM 23/04/03 -0500, you wrote:
>histonet@pathology.swmed.edu