Developing film in fermented oak gall solution ...

Alan Johnson said:

I don't think it is possible to develop silver iodide latent image in gallic acid alone.

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I am sitting here thinking and I guess I have never completed the development of a silver idodide calotype with just galic acid myself. I've added differing amounts of acetonitrate and I've added it at different times, but I haven't developed a calotype all the way without it. But I believe others have, with development times ranging from 20 or 30 minutes up to hours or even overnight.

Edit: and what Michael typed at same time as me probably explains this. So that would still be called "physical development"... very interesting!

pdeeh said:

There's a lovely site devoted to Albumen printing (http://albumen.conservation-us.org) that contains an electronic version of "The Silver Sunbeam" by John Towler M.D., first published in 1864 as a "A Practical and Theoretical Text-Book ON SUN DRAWING AND PHOTOGRAPHIC PRINTING ..."

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If I ever try this, I think I'll skip the part about tasting it to see if it has an "astringent" taste!

I hope that site is safe since I've visited it many times!

It's amazing what the 18th and 19th Century scientists (and no doubt their predecessors for centuries, if not millennia) would put in their mouths.
I think Humphrey Davy was in the habit of having a bit of a nosh on substances to see what their taste might add to his stock of knowledge, and he wasn't the only one by any means.

NedL said:

I am sitting here thinking and I guess I have never completed the development of a silver idodide calotype with just galic acid myself. I've added differing amounts of acetonitrate and I've added it at different times, but I haven't developed a calotype all the way without it. But I believe others have, with development times ranging from 20 or 30 minutes up to hours or even overnight.

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I'm not sure if Gallic acid might be like Amidol, which develops at low pH, but:
From the patent I linked to,

Formula 6585
Water............................................100ml
Gallic Acid......................................0.34g
Sodium Sulfite, anhydrous................2.5g
Sodium Carbonate monohydrate........2.5g
Acetic Acid, to adjust pH to 10.0

"Formula 6585, in which Gallic acid was the sole developing agent, produced no development in times up to eight minutes at 68F."
I expect those who worked with the calotype process may know better but a source would be useful.

Alan Johnson said:

....I expect those who worked with the calotype process may know better but a source would be useful....

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I seem to be finding some references that imply calotype development with gallic acid alone is "chemical development", and that when you add AgNO3 to intensify the negative, it is physical development.

In Alan Greene's book, on page 161 where he describes calotype development, step 7:

The negative images should start to materialize within the first 2 to 3 minutes of development. Full development is normally achieved in gallic acid alone within 10 to 20 minutes. Developing longer than 20 minutes results in fogging.

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Step 8 goes on to say that if the negative seems overexposed, you can add a little acetic acid. Step 9 says if the image seems underexposed you can add some AgNO3.

In the description of the Talbot process at the calotype society, in step 12, it says:

While it is only the Gallic Acid that is absolutely necessary for developing the silver image (through chemical development) the addition of the Aceto-Nitrate of Silver enhances density by selectively redepositing silver on the image (by physical development.)

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Also here, where various people describe their calotype processes, several people use mention using gallic acid and only adding AgNO3 if needed, e.g.:

Develop negative by floatation on a 0.4 to 0.8% Gallic acid solution and add silver if slow to develop[ or pull development by adding acid to developer

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In my own experience you can certainly observe the image emerging in gallic acid alone, but as I mentioned, I've never gone on to finish the development without adding some silver.

By the way, while looking for these references I came across this history of priority in using gallic acid for latent image development. It does not seem to be directly related to the current topic, but it is fascinating to read.

What is an oak gall?

kb3lms said:

What is an oak gall?

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Oak Gall

I can see some when I look out the window of my living room, in the oak tree next to our house. I have no excuses whatsoever for never having experimented with them!

pdeeh said:

It's amazing what the 18th and 19th Century scientists (and no doubt their predecessors for centuries, if not millennia) would put in their mouths.
I think Humphrey Davy was in the habit of having a bit of a nosh on substances to see what their taste might add to his stock of knowledge, and he wasn't the only one by any means.

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At the time it was considered to be part of the chemical's description to also include taste. The very poisonous element beryllium was originally named glucinium because of the sweet taste of many of its compounds.

NedL said:

Oak Gall

I can see some when I look out the window of my living room, in the oak tree next to our house. I have no excuses whatsoever for never having experimented with them!

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Remember to only pick those with an exit hole - this means the wasp has bored its way out (although of course it will in a proportion of cases mean the larva has died or hasn't developed.)

You'll have to check which type of gall you have, and thus which species of wasp is likely to be causing them, as they all have slightly different laying and emergence patterns.

Natural history and photography in the same thread ... what's not to like?

Although the calotype society says gallic acid alone gives chemical development, it seems to me more likely that it actually acts upon silver nitrate from the sensitizer. This is physical development as discussed here:
https://books.google.co.uk/books?id...ge&q=gallic acid physical development&f=false

pdeeh said:

I'd already emailed them, .

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Let us know when the webmaster replies. If it is a false positive then I'd expect action by the site very quickly as any newcomers won't bother and presumably sites live or die by their safety record. I'd love to have a look but won't as long as the warning persists

Thanks

pentaxuser

Alan Johnson said:

Although the calotype society says gallic acid alone gives chemical development, it seems to me more likely that it actually acts upon silver nitrate from the sensitizer. This is physical development as discussed here:
https://books.google.co.uk/books?id...ge&q=gallic acid physical development&f=false

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Thanks! It took a while for the details of what you are saying to sink in. You may well be right. The process I'm using is intermediate to the wet and dry processes mentioned in your link. My paper is not waxed, but I do wash it completely ( 10 minutes in changes of distilled water ) after sensitizing and then let it dry overnight. It must then be exposed within about a day and does not have the keeping qualities of a washed waxed calotype. Just the fact that I've always added some aceto-nitrate of silver during development is consistent with your point.

I am just about to embark on testing a new kind of paper for this process, so along the way I will see if I can develop one with just gallic acid. Who knows, maybe I'll try to develop one with some "fermented gall juice" too.. if I can figure out which kind of wasp makes the galls on my oak tree!

Edit: Another thing that is consistent with your point is that Greenlaw's instructions for developing his calotypes seem to indicate that he always adds acetonitrate to the gallic acid, not optionally. That this is different from "normal calotype" developing was noted in discussions, but the discussion may have missed the distinction between wet and dry calotypes that contain residual AgNO3 from sensitizing or not. Just as you say!

Hi Alan,

Here are the instructions I started with for my own exploration of calotypes. If you look at the discussion after the instructions, you can easily see where my impressions came from! I've also read Alan Greene's book, and the part I quoted above was for WET calotypes! His instructions for dry waxed calotypes on page 177 confirm what you are saying exactly:

Stir in one or two eyedroppers' worth of 8 percent silver nitrate solution into the gallic acid, just before beginning development, to account for the loss of excess silver nitrate in the negative that was removed in rinsing the sheets after sensitizing.

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It seems to me that this approach might work for developing film too???

Thanks for staying patient with me, and for guiding me toward understanding what I'm doing better!

Ned

P.S. one more detail. I said above that I can see the image emerging in gallic acid alone, before adding the acetonitrate of silver, and that is true. But it is also true that every calotype I've made so far has had a faint visible image on it prior to development. So it may be that what I'm seeing in the gallic acid is not development of a latent image at all, but of the weak "printed out" image... does this idea make sense?

Pdeeh, I can move along to another thread if this is getting too far afield from your original post, but it does all have to do with what kind of development is happening in gallic acid.... or in fermented oak gall concoction....

Also APUG is great: this discussion got me moving again and I'm off to idodize some of my new paper right now!

Hi Ned,
IMO the thread by its nature involves early processes.
The image that you see on the calotype before development seems to me to be normal though I have never made one, it is mentioned here "extremely faint image":
http://www.historygraphicdesign.com/industrial-revolution/the-industrial-revolution/635-calotype

IDK if modern silver bromide film emulsion can be developed in gallo-nitrate, a search did not find any reports of it.
Thanks for your educational comments.

NedL said:

Pdeeh, I can move along to another thread if this is getting too far afield from your original post, but it does all have to do with what kind of development is happening in gallic acid.... or in fermented oak gall concoction....

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Not at all Ned, this was exactly the sort of discursive discussion I hoped it might prompt (so long as we can avoid the subject of other people's bloody websites )

However, what does interest me in this context is less the calotype business and more iron-based processes.

Once upon a time, for instance, there was a beast called "ferro-gallic" paper, used mostly for document and drawing copying. I only became aware of it when I found a 30 yard roll of the stuff in a darkroom I was clearing. At (a minimum of) 70 years old, it had long since lost all sensitivity and indeed crumbled to flakes in my hand thanks to the acidity destroying the paper. It also smelled vile.

Also known as Colas' Process, it gave a black and white image rather than the blue of a cyanotype, and used essentially the same ingredients as iron gall ink - gallic acid and ferrous sulfate were used to coat paper, exposed under UV light and then "developed" in water. It was a refinement of a similar process which had used gallic acid and ferric sulfate and was then developed using oxalic acid.

I thought it might be fun to try.

Unfortunately I've pretty much run out of galls, and they don't seem at all common on the oaks round my part of the world - my recent batch had come from a couple of hundred miles away, picked while I was staying away for christmas.

Mind you I've got my work cut out trying to make decent salt prints, so I probably don't need any further distractions ...

I've got a sheet of freshly iodized paper drying right now. The earliest I might sensitize it will be tomorrow evening, and the earliest I might expose and develop will be Monday. Since my goal is to make a calotype that will print well without stains or fog, I'll probably add aceto-nitrate of silver to the gallic acid during development unless it looks severely overexposed ( not likely ). But this thread helped get me moving along again and I'm excited about working with my new paper. If I get successful results over the coming weeks then I'll be iodizing the paper in batches and making more calotypes. At that point, I might experiment with gallic acid alone to see if I can confirm this thread... also maybe I'll start some galls fermenting. It would be fun to see if we can develop film or paper in some fermented gall juice with a squirt of AgNO3 added.

pdeeh said:

However, what does interest me in this context is less the calotype business and more iron-based processes.
...

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Possibly related to this. The calotype process I'm using is from Greenlaw. There is a surprisingly minor variation of it that is iron-based. I think it is described in Abney's instructions for photography in the section immediately after the section on Greenlaw's process. I'll look later this evening and post a link here if I can find it. Right now the sun is out and it's a beautiful day, so I'm off to walk the dog and maybe make some pinholes...

OK I'm back. Here's the link. On page 168 of Abneys Instructions in Photogaphy.

The difference is pretty minor:

1) the calotype may be sensitized using a solution of AgNO3 w/o acetic acid.
2) It can be soaked in a salt solution prior to washing and drying.
3) Development is with ferrous oxalate + KBr, or with ferrous citro-oxalate. Instead of gallic acid.

Thanks Ned.
That book is avialable in electronic form here: https://archive.org/details/instructioninph00abnegoog for anyone who hasn't got a copy

pdeeh said:

It's amazing what the 18th and 19th Century scientists (and no doubt their predecessors for centuries, if not millennia) would put in their mouths.
I think Humphrey Davy was in the habit of having a bit of a nosh on substances to see what their taste might add to his stock of knowledge, and he wasn't the only one by any means.

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And Isaac Newton shoved a darning needle behind his eye to help discover the laws of optics and for that we should all be pleased.

indeed he did - a bodkin no less