Most microscope slides these days are borosilicate glass, which is quite transparent to 3000, (much more so than DIS is), so check what you have; it may be OK. jim APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 23 in the apo35-dis archive. You can find APO the archive on http://www.astro.princeton.edu/APO/apo35-dis/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-dis@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO