John's comments were superb.  We have, on occasion, not presubbed the
slides but added semiliquid  subbing solution to a waterbath, with
excellent results.  The subbing solution was preserved with a few thymol
crystals.  Floating out the section on dilute subbing solution in
the waterbath is just another twist to the story.  The only drawback
I can see, is dunking fingers in the water (not good technic!) and contact
with chromium on skin, with care and skill this can be avoided.  
The waterbath capacity 1 liter, so 10mls subbing solution for every liter
of water.  This was particularly nice for extremely large bone sections,
picked up on 3 x 4 or 2 x 3 inch slides (whole mid saggitial sections
of sheep tibia, distal ends, and even proximal of femurs)
If you do this, be sure to check the subbing solution for growth floaters
frequently or just make up smaller amounts.  

Gayle Callis