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Archives of an email list on the history of binoculars. - page 18 / 150





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Subject: Fungus

From: Peter Abrahams

  A long time ago, I ran across a reference to an article in a journal that I never thought I'd see: Indian Journal of Technology, from 1963.  But University of Washington, Seattle, has it, and I copied it a couple of months ago.  Footnoted in this article were some hopelessly obscure military publications; and also a text from the journal 'Nature', which is found in any college library.  The Nature article has information that is possibly very useful.  During WWII, programs to research & treat fungus in optical instruments were undertaken in Australia.  They began using the compound sodium ethylmercurithiosalicylate, now known as Thimerosal & widely used in vaccines, eye drops, nasal sprays, ear & other topical products.  It was mixed with the paint & sealers used inside the binocular body.  This was quite effective, and I believe Thimerosal shouldn't be too hard to obtain.

  Have any of the repairmen / restorers on this list used this compound?

  Are there any physicians or chemists who know how a person could obtain this?

  I scanned these articles, added some other texts, and placed on the web site a long page on fungus in optical instruments:


  These WWII articles mention lens cements - balsam and n-butyl methacrylate.....I'm not sure what methacrylate is.  I know there were synthetic lens cements 60 years ago, presumably this is one of them.  They also use the term 'luting', which was new to me and means sealing.

  Can anyone locate this document; it could be very helpful:   Baker, P.W.  Bibliography on Tropic Proofing of Optical Instruments.  Royal Radar Establishment Tech. Note 747.  Malvern, England. 1969.

  A Zeiss question: Some on line sources note a paper on lens fungus issued by Zeiss in the 60s, but there are no citations....does anyone have a reference to this?

  Here is the introduction I put with fungus.txt:

  Many old optical instruments have fungus growth on a glass surface.    Fungus does not look like haze but has an appearance like hairs or tendrils branching from a center.  While the fungus can be removed by cleaning, it frequently has etched the glass, since fungi secrete enzymes and acids to chemically alter their environment so they can absorb nutrients.  This etching requires repolishing, which if done unprofessionally will ruin the instrument.  It is not possible to tell if the glass is etched until the fungus is cleaned.  Maintenance of optical instruments involves prevention of future fungus problems, especially if located in damp regions.

  To sum up the lengthy documentation below:

  --WWII research programs on fungus in optical instruments (Turner, below) used sodium ethylmercurithiosalicylate, now known as Thimerosal and widely used consumer medical products.  When mixed in paint used inside the binocular, this was found effective at preventing fungus.  It is not known if Thimerosal is so used today.

  --Hydrogen peroxide, or bleach, can be used to kill fungus.

  --Leitz documents describe a fungus treatment of 94% distilled water, 4% clear ammonia (for cleansing) and 2% hydrogen peroxide (to kill fungus).

  --Carl Zeiss Oberkochen, dept. KuDi, sells:   Fungus Cleaning Agent "Fungusreiniger NEU".  Dilute with ethyl alchohol, leave on glass for one hour or more, then clean.  Not poisonous but avoid contact with skin.  100ml bottle, INR 0117.362   500ml bottle, INR 0117.361   1000ml bottle, INR 0117.360

  --Notes on treatment & prevention are found at the end of this text.


Subject: Danish Galilean

From: <mikedenmark@___ele.dk>

  Well, in response to the request for more people to respond to the list, I have added a page on my geocities homepage.

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