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Document number: 6255
Date: 26 Jul 1849
Recipient: TALBOT William Henry Fox
Author: MALONE Thomas Augustine
Collection: National Science and Media Museum, Bradford
Collection number: 1937-4973
Last updated: 12th August 2010

London 122 Regent Street <1>
26 July 1849

To H. F. Talbot Esq


Since our conversation in May last, when it was agreed that the Hyposulphite of Soda, should not be used for fixing the “chloride” positive pictures; as it had proved to be a dangerous agent; I have made many experiments which seen conclusive, & will I trust prove satisfactory to you.

Herr Kuhn has assisted Mr Henneman with the portraiture so that I could devote nearly all my time to the investigation of the difficulties which existed.

I think you will find those difficulties are now much lessened, if not all removed. The gaining of time for uninterrupted experimenting, is the only advantage derived from the arrangement made with Herr Kuhn – his pictures are not preferred to our own.

I have by analysis found that the quantity of silver in a large picture is so small that it is surprising they have not all of them faded away. The process used hitherto even when strictly carried out leaves in the paper more hyposulphite of soda than is required to combine with the silver of the picture to form the hyposulphite of the latter or rather the double hyposulphite of soda & silver. The fainter tints containing the least quantity of metal are soon destroyed. The shadows require a longer period. Time & moisture probably aiding the diffusion of the salt.

The hyposulphites being soluble there can be no method for the perfect restoration of the picture. I have restored those faded by Iodine & have no doubt of succeeding with those destroyed by Chlorine.

Some spring waters contain chloride of calcium & other deliquescent salts which would hasten the fading in some instances. Some of the pictures made at Reading do not fade so soon as those made elsewhere. We have a specimen which has been five years getting fainter while others change in twelve months.

The difference in the impurities of the water may explain this. Distilled water does not ensure fixing.

The well known difficulty of separating by washing, some salts from metallic oxides & other precipitates may apply here so that Mr Henneman’s picture fading after distilled water had been used may be understood now that we know the quantity of silver spread over fifty six square inches, often, does not exceed twelve hundredths of a grain.

In the beginning of June I for the first time tried an experiment that I had long thought of as likely to throw some light upon the nature of the change which takes place when chloride of silver is exposed to the light about which change so much difference of opinion exists among chemists.

It then occurred to me that the substance I used would decompose hyposulphite of soda or even remove chlorine if any existed in the fibre of the paper – but then I feared that the image or the paper would give way under so powerful a reagent.

As it happens nothing can be more satisfactory than the result the hyposulphite is decomposed & the image & paper both positive & negative come out uninjured from a concentrated & boiling solution. The material evidently cannot destroy the picture even if not all washed out.

Hyposulphite of soda cyanide of potassium caustic ammonia & other fixing agents are all capable of destroying the pictures.

The class of substance I have fortunately chosen seems fortunately to be the only one both harmless & efficacious at the same time.

The colour produced by this new treatment is green a characteristic test of the completion of the process. This colour being disagreeable I sought & found a fine brown or bistre tint & that by a substance not capable of fading the picture.

The brown colour – neither red nor purple – is universally admired in an accidental specimen we have long had by us – so that I have not drawn conclusions to suit my experiments.

I have no doubt the colour can be commanded always tho the fixing is of greater importance than the colours.

I should like to show & explain to you the experiments as soon as possible, that you may judge of their accuracy.

If most convenient to you I could go to Lacock Abbey a few hours would suffice for the purpose.

I think it very fortunate that we now have a process to meet objectors with as Mr A. Taylor of Guys Hospital has spoken of the fading publicly at the Royal Institution <2> & at Lord Rosse’ <3> Soiree where our pictures were exhibited & much admired.

A scientific amateur Mr Vernon Heath <4> nephew of the late Mr Vernon whose pictures are in the National Gallery lately sold his camera “in disgust” because he could not fix his sun pictures. A clergyman taught by us also complains that after all the care he has bestowed upon his pictures they fade.

I fear that our business has been injured by the prevalence of the idea of the fading. We are constantly & unpleasantly cross-examined on the subject.

The Art Union <5> copies containing Sun pictures seem to have done harm the Artists who have them are interested in giving every publicity to the fact of their growing fainter.

Will it not be necessary – if you approve the new process – to add to your former patents & so give a new start to the invention; which would benefit the Regent St establishment; especially as some one else may discover the method & patent it. Such unfairness has been practised in other scientific inventions.

I remain Sir Most obediently yours
T A Malone

H F Talbot Esqr
Lacock Abbey
Chippenham England


1. The London address of the Sun Picture Rooms, proprietor Nicolaas Henneman (1813–1898), Dutch, active in England; WHFT’s valet, then assistant; photographer.

2. Royal Institution, London.

3. William Parsons, 3rd Earl of Rosse (1800–1867), astronomer & MP.

4. Vernon Heath (1820–1895), photographer & author.

5. He was referring to a project nearly three years before, when WHFT attempted to expand the awareness of the calotype through the pages of the Art-Union Monthly Journal of the Fine Arts and the Arts, Decorative, Ornamental (launched in 1839, the same year as photography). It was a lavishly illustrated journal that included many demonstration pieces. An original mounted Talbotype was bound in each copy of the June 1846 Art-Union, v. 8 no. 91, facing p. 143. Hall originally estimated that he would need 4000 or 5000 prints, but in the end 7000 were required. Since each print had to spend some time in the sun under the negative, Henneman pressed every available negative into service, leading to a great variety in different copies of the journal. Hall must have heard from some skeptical artists, for he felt compelled to explain in the next issue that the prints 'were taken from the actual objects they represent; they were, strictly, copies from NATURE; in no case had a print been made use of for the purpose of transfer' - 'The Application of the Talbotype', The Art-Union, July 1846, p. 195. The final effect of this effort was costly to WHFT, both in out of pocket expenses and in reputation. The production of so many prints in such a short time span with the approach of winter suffered from a paucity of sunshine and Henneman's inability to supply (and afford) sufficient warm water for adequate washing. Many of the prints began fading almost straight away, and this fiasco was one of the factors that led WHFT to abandon printing with silver in favour of his photographic engraving and later photoglyphic engraving, both expressed through time-tested printer's ink.

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