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Document number: 4186
Date: 26 Jan 1841
Recipient: TALBOT William Henry Fox
Author: SCHAFHÄUTL Karl Emil von
Collection: British Library, London, Manuscripts - Fox Talbot Collection
Collection number historic: LA41-3
Last updated: 25th July 2012

the 26th of Jany 1841

To Fox Talbot Esqure &c &c London.


I receaved [sic] from Professor Dr von Ettingshausen <1> of Viena, who is one of your greatest admirers, a letter in which he gave me a detail of the photographic procedings at Viena,[sic] asking of me at the same time very ardently, to write to him (as soon as your new improvement <2> in Photography were made known public in London) all what I was able to ascertain about it. As I had left London before I receaved the Professors letter, and was thus unable to comply with his wishes – I took the great liberty to address myself at once to you, beging of your kindness, either to write a few lines to me at Munich, or at once to Dr von Ettingshausen, Professor der Physik etc (Landstrasse 58) Vienna when you think proper, to make your Secret known – we both, von Ettingshausen & myself would be very happy to receave any kind of information from you, and offer our services in return at any time you should like to make use of them. von Ettingshausen got the first notice of your new invention from Biots <3> comunication, in the [illegible] – and he agrees perfectly with Biot, that the Photographic can be of any real use only when we shall be able to use paper instead of metallic surfaces. You are perhaps aware, that Prof. Petzval <4> in Vienna invented a new combination of achromatic lenses, in order to make the whole surface of the lens or the whole Diameter of the aperture of the camera obscura useful, & the Professor is going to construct s all dioptric instrument [sic] according to this new principle. I procured one of these camera obscuras for the P[illegible] of Mr Daguerre <5> in London Mr Claudet <6> for procuring portraits [sic]. Each of the achromatic lenses has an aperture of 1½ inch Diameter & both act together with their full apertures as a single achromatic lens of 5½ inch focus. The Diameter of the portrait or image in its greatest distinctness [illegible] sharpnes in the outlines is more than 4 inches. In the autum of the last year Prof. Petzval made the first experiments. The plate was prepared with tincture of Iodine according to the process of M.[Asherson?] of Berlin. On a clear day – the person to be portraited sitting in the shadow – never more than two Minutes were required to obtain a perfect portrait – the glass or other artificial means for illumination were never made use of. The preparation of the plate now is: Iodine is exposed to [illegible] vapours of chlorine, and then the watery solution of the obtained brown semifluid combination used exactly as the tincture of Iodine. A portrait never wants more than 8–10 Seconds to be completed and Professor Ettingshausen particularly mentions the beautiful effect, which whole groupes of figures make obtained in this way. According to von Ettingshausen the plates become still more sensible, when the plates, first covered with iodine in the usual way are held over a feeble solution of Chlorine in water till the plates have assumed a feeble reddish tint – viz in the same way as I used to prepare my paper covered with the nitrate of silver. Such a plate needs exposure to the light in the shadow only 2 Seconds and in direct sunlight less than one second; but the experiment after result is not certain. Professor v Ettingshausen says the plates I made by Daguerre himself were very beautiful, but he saw the last year in London scarcely one plate which was good or perfect. The brothers Natterer <7> of viena [sic] made another interesting experi discovery – they found, that a plate treated in the common way with Iodine and afterward exposed in the dark for a short time to the vapours of dichloride of sulphur when brought into the camera obscura – after one minutes action of the light no image is to be seen – but it appears immediately – when the plate is slightly heated or exposed to the light but it disappears, when [illegible] with the usual work. Prof von Ettingshausen thinks this experiment may have some analogie [sic] with one of yours mentioned in a letter to Biot – of such an image appearing like produced by Magic powers.

Trusting to your kindness I again repeat my prayers to let either von Ettingshausen or me at Munich know in a few lines about your new discovery as soon as you think it proper to divulge your new process.

Offering to you my humble service in any way you may choose I have to [sic] honour to be with the greatest respect

Sir Your very obedient Servant
Charls Schafhaeutl M & PhD.

(Munich Arcisstrasse No. 15/2)


1. Andreas Ritter von Ettingshausen (1796–1878), Austrian professor of mathematics, who made daguerreotypes for Prince Metternich.

2. This has probably to do with WHFT’ discovering ‘a means of increasing the sensitivity of papers which are sensitised by light’. [See Doc. No: 04184].

3. Jean-Baptiste Biot (1774–1862), French scientist.

4. Joseph Petzval (1807–1891). [See Doc. No: 08590].

5. Louis Jacques Mandé Daguerre (1787–1851), French artist, showman & inventor.

6. Antoine Françoise Jean Claudet (1797–1867), London; French-born scientist, merchant & photographer, resident in London.

7. Dr Johann August Natterer (1821-1900) and his brother, Josef (1819-1862); they were early experimenters in Vienna who increased the sensitivity of daguerreotype plates.

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