I have used concentrated nitric acid on finely divided (black) silver
deposits.  It does dissolve them.
Nitric acid also dissolves black deposits of lead.

Allen A. Smith, Ph.D.
School of Graduate Medical Sciences
   Podiatric Medicine and Surgery
Barry University
Miami Shores, Florida
----- Original Message -----
From: Karen Pawlowski 
To: Histology Net List Server (E-Mail) 
Sent: Friday, November 02, 2001 10:36 AM
Subject: Method for Removal of Silver Deposits on Glassware


> Hi all,
>
> An associate of mine, Kumathu Paulose, asked if I would post the
> following method that he developed for anyone who wants it. I haven't
> tried it, but I know that he is a very experienced histotechnician.
> I hope that someone finds it useful and I'm sure he would appreciate
> feedback. Just post it to the net and I'll make sure he gets it.
>
> Karen Pawlowski
>
>
>
> Removal of Silver Deposits from Glassware and Plastic Dishes
>
> In the histology laboratory, metallic silver is often deposited on
> glassware and plastic dishes after the use of silver stains.  This
> deposit of silver can be easily removed within a few seconds by the
> following method.
>
> Pour concentrated nitric acid into the container having the silver
> deposit. The metallic silver reacts with the nitric acid to form silver
> nitrate and hydrogen is liberated according to the following equation:
>
> Ag2 + 2HNO3 -> 2AgNO3 +H2(released)
>
> All of the silver deposits from the container will be removed in less
> than one minute.  This reaction needs to be carried out under a fume
> hood wearing gloves.  Care should be taken when handling strong acid.
>
>