Oak Tree Galls on their way towards becoming Gallic Acid


During this week last year we celebrated the birth of the Talbotype by referring back to a 2015 blog, To the Calotype: Happy 175th Birthday!  That outlined the astonishing moment of discovery – astonishing even to Henry himself – that a previously undetected latent image could be exploited to drastically reduce exposure times, thereby rendering his negative process at once more practical and perhaps more importantly greatly expanding the range of his subject matter.  Gallic acid was the secret ingredient that he so carefully excised from his notebook page.  I won’t fully repeat the story here, but may I recommend that you review that blog for a more complete description of how all this came about?
And just to remind ourselves, Talbot’s first photogenic drawing process was a print-out process where the image was formed completely using solar energy.  It was stunning and Talbot made many good negatives with it, but it never would have achieved commercial maturity.
I like to think of Talbot as a serious scientist – and he was – but I am even more thrilled by the peregrinations of his extraordinarily fertile mind.  Those of you who have plowed through his notebooks – especially the ones most relevant to photography which he simply labelled ‘P’ & ‘Q’ – realise that his imagination bubbled up a continuous flow of discontinuous thoughts.  While the original notebooks are understandably protected from excessive handling, it is possible to look at P & Q in facsimile, examining the ebb and flow of his thoughts as he planted them on the pages.  This illustration is of Q35, from 6 September 1840, the page immediately before he began recording the rapidly unfolding discovery of the calotype.  At the top is a proposal for a partitioned glass tube where he might use galvanic current (electricity) to decompose ‘divers liquids’ for analysis.  Next comes a thought about atmospheric railways, a subject of intense interest to him and his peers.  At a time when portable engines were puny and largely impractical, many attempts were made to utilize a central vacuum pump.  There was a channel cut between the tracks and this sealed over by two leather flaps.  Each carriage had a piston that reached down into this channel.  Periodically spaced vacuum pumps sucked the air out of the channel, propelling the piston and dragging the carriage along with it (older readers might remember the piping in department stores where a vacuum tube system transported your payment to the office, then returned the receipt – you can see an ultra modern version of this in daily operation at B & H Photo in New York).  The idea was a good one save for the fact that durable flexible synthetic materials were not available so leather was generally used.  It dried out in the sunshine, or more often was gnawed on by rats, degrading the vacuum.  Talbot’s final thought was about how to produce platinum wire using electricity.  All this in one page!
manicule-blog- f9f5eeYou are about to see what some might consider to be really ugly or really boring photographs – but they are very rare and even more rarely seen – and they are critically important.


SC2466_1937-1378The next full page, covering experiments on 17-18 September 1840, recorded his discovery of the Leucotype, an extraordinarily rare direct positive process not unlike that of Hippolyte Bayard.  While the creation of a negative may seem to have obvious advantages to us today, making prints from one was sometimes regarded as an unnecessary complication.  If you only needed one image and wanted it as quickly as possible (or if you wanted to compete directly with the Daguerreotype) creating a positive right in the camera could be an advantage.  Talbot called it the “Leucotype, or Positive Photogenic Drawing.”  He took a double-Waterloo paper, washed it with a strong silver nitrate solution and immediately darkened this in bright sunlight.  Dried and then washed with potassium iodide, it could be exposed wet in the camera and the previously-darkened paper bleached in proportion to the intensity of light, forming a direct positive image that could be fixed with simple hot water.

Here he has rendered a scrap of ribbon, perhaps as a test of colour sensitivity, but with enough sharpness that one can still make out the threads.  Even more importantly for us today, Talbot recorded a great deal of experimental information.  The date is clear, giving us a positive cross-reference to the notebooks, an “X” marks the sensitive side, the “2d” indicates a two second exposure, and the “2W” is, of course, the double-Waterloo.  I’m sure that the reference to the great battle was not an accidental one but this simply signified a bromide-based or fixed photographic process.



Unfortunately there is no visible image left on this experimental negative, but Talbot’s inscriptions once again help us fill in the story.  It is tempting to try to make out something until one realizes that the J Whatman watermark is the only really well defined image. From his notes on the artefact itself we can see that this was a “New paper”, exposed on 22 September 1840 for two minutes, and then fixed in potassium iodide. This was recorded in blue ink.  The really important information was hastily added in pencil the next day.  “Sept 23 washed with E & brought out by spont[aneous].”  The ‘E’ was his exciting liquid, the gallic acid developer that was the great breakthrough in the developed-out process that was to become known as the calotype or Talbotype.  Instead of solar energy doing all the work of reducing the light-sensitive silver salts to the metallic silver image, a chemical developer built on and greatly amplified the invisible changes that a brief exposure to light had wrought.



It is a miracle that these primal steps towards the calotype process exist at all.  I’ve had to intensify (digitally, non-destructively) this negative of the chimneys on the roofline of Lacock Abbey to make it more visible, but when examining the original in just the right light you can still make out the image.  From his annotations on the verso we can see that Talbot made this on 22 September 1840, with a five minute exposure under cloudy conditions, and then fixed it with potassium bromide.


And now we come to what I consider one of the most extraordinary of all Talbot’s images.  What is left of the negative is not much to look at but on its verso we gain the valuable information that he took this on 29 September 1840 with a one-minute twenty-second exposure.  In less than a minute and a half he created an enormously complex image of the terra cotta statue of Diogenes in a recess of the great hall of Lacock Abbey.  While the negative itself is degraded, at least one really spectacular print from it survives in an album compiled by Lady Elisabeth.



I’ve reproduced this in a previous blog  but I am sure that you can forgive me wanting to share it again.  I took this Ektachrome slide at the Science Museum in the 1970s during a rare occasion when the print was temporarily extracted from the slits in the album page.

Henry Talbot captured his Diogenes barely a week after he had first discovered the calotype process.  From a technical point of view, it is a fleeting image that exists only briefly as the sun is setting and the pattern from the front windows races across the room.  What could be a more poignant subject than the Greek cynic philosopher using light in search of truth?  Had no other photograph ever been taken after this one, we could proudly state that photography had exited the stage on a high note.  I don’t mind saying that it remains one of my absolutely personal favourite Talbot images.  And in that it has considerable competition.  What better way can we say Happy Birthday to the Calotype!

Larry J Schaaf


• Questions or Comments? Please contact Prof Schaaf directly at larry.schaaf@bodleian.ox.ac.uk  • Peggy Osterkamp pulverizing oak tree galls (in her case, to make fabric dyes rather than photographic chemicals).  • WHFT, Pages from Notebook ‘Q’ – these are fully published in facsimile, with commentary, by LJ Schaaf, Records of the Dawn of Photography: Talbot’s Notebooks ‘P’ & ‘Q’ (Cambridge: Cambridge University Press, 1996).  WHFT, Ribbon, Leucotype direct positive, 17 September 1840, National Science and Media Museum, Bradford, 1937-1378; Schaaf 2466.  • WHFT, New Paper, experimental calotype negative,  22-23 September 1840, Fox Talbot Collection, The British Library, London; Schaaf 2468. •  WHFT, Roofline of Lacock Abbey, calotype negative, 22 September 1840, Smithsonian’s National Museum of American History, 1995-206-51; Schaaf 2469.  •  WHFT, Diogenes in the Great Hall of Lacock Abbey, 29 September 1840; calotype negative, Smithsonian’s National Museum of American History, 1995-206-93; salted paper print, National Science and Media Museum, Bradford, 1937-365/23; Schaaf 2478.