Jennifer:

	Never heard that explanation before.  The "fine dust" is said to be
produced by action of moisture on glass, which produces hydrochloric acid,
and which etches glass.  It was for this reason that Clay-Adams introduced
hermetically sealed cover glass cases with enclosed silica gel.  The latter
finds its way today into individual boxes of cover glasses with teeny tiny
silica gel bags.

	Richard-Allan introduced the cleanest cover glasses around in the 1970s by
cutting and packing them in environmentally clean rooms: positive pressure
rooms, temperature and humidity controlled, HEPA filtered air, technicians
in special suits, etc.  I don't know whether their cover glasses are
manufactured in the same fashion today.

	Larry Barnickel, an early Richard-Allan salesman, told me that one of the
tricks of the trade years ago was for a salesman to go into a lab, spot a
competitor's cover glass, pick up an ounce AFTER WETTING HIS THUMB AND
FOREFINGER, allowing the moisture to wick between the cover glasses to
cement them together, and then throw the mass on the countertop exclaiming
how dirty they were!

Gary W. Gill

-----Original Message-----
From: MacDonald, Jennifer [mailto:jmacdonald@sach.org]
Sent: July 26, 1999 10:47 AM
To: histonet@Pathology.swmed.edu; 'Gayle Callis'
Subject: RE: Inquiry on clean coverslips needed


A few years ago I was told that fine glass dust is used to keep the
coverglass from sticking to each other.  This was for automatic
coverslipping instruments.