From well before the time when William Henry Fox Talbot ventured into the realm of photographic experiments, the effects of silver nitrate, salts and light were known to several men of science. We credit Talbot with the invention of the photographic negative because it was his experiments which spurred a long line of successive developments in photography. In 1844 The Pencil of Nature became the first widely published book, although delivered in six individual fascicles, to be illustrated photographically. Talbot had a close friendship with Sir David Brewster, who was principal of the University of St Andrews from 1838 to 1859. Brewster was made aware of Talbot’s work through their ongoing correspondence, and he put in a library acquisition request for the Pencil of Nature in early 1844. In this week’s Historical How-To we decided to recreate Talbot’s photogenic drawing experiments using The Pencil of Nature, now held in our collection, as our inspiration and guide.
It is important for we modern-day-readers to think back to a time when the likeness of a building, object, landscape scene or even your dear old aunt Bessie could only be captured by an artist, and the quality of said likeness would vary greatly depending on the aptitude of your chosen artist. Although surrounded by a family of women who were gifted artists, Talbot was afflicted with the inability to draw, even with the aid of a camera lucida. His experiments were fuelled by his desire to find a way to create an image without the use of an ‘artist’s pencil’. This was a strange and foreign concept at the time, so much so that he inserted a ‘Notice to the Reader’ on the first page of each fascicle explaining this unique feature of his work:
The Pencil of Nature consists of 24 photographic plates, most of which are salted paper prints from calotype paper negatives, however two plates, namely VII and XX are photogenic drawings, one of a plant leaf and another of a piece of lace. A photogenic drawing is, in essence a highly detailed shadow that is captured and fixed through a series of chemical processes.
Because the specific chemical requirements are not explained in this publication, the enthusiastic Victorian reader would have had to delve deeper into the scientific literature of the time. Talbot does however explain the mechanics by which one would ‘capture a shadow’.
A piece of writing paper was sensitised by the application of two coatings; one of sodium chloride (salt) and the other silver nitrate. Talbot used normal table salt, however as regular salt today is often iodized, we used sea salt flakes diluted in water. Once that layer was dry we added the silver nitrate, which had been dissolved in distilled water. At this point the paper becomes sensitive to light so the silver application must be carried out by ‘candle light’ or in our case a dark-ish loading bay. The process is actually quite slow, so a little bit of light from the adjoining room had no real effect. In the 1830s the papers would have been hung to dry – we cheated a bit with the use of a hair dryer to speed things along as nothing really dries quickly here in Scotland.
Talbot’s instructions in Plate VII in the Pencil of Nature describe the use of a printing frame.
A leaf of a plant, or a similar object which is thin and delicate, is laid flat upon a sheet of prepared paper which is moderately sensitive. It is then covered with a glass, which is pressed down tight upon it by means of screws.
This done, it is placed in the sunshine for a few minutes, until the exposed parts of the paper have turned dark brown or nearly black. It is then removed into a shady place, and when the leaf is taken up, it is found to have left its impression or picture on the paper.
– William Henry Fox Talbot, Plate VII, in The Pencil of Nature
Victorian printing frames can be a bit hard to come by, but these were put together using thick glass, four bull-dog clips, a felt lined board and a bit of duct tape. It may not look as pretty, but does the job just as Talbot instructed. We found that ‘a few minutes’ of English sunshine in August equated to about 30 minutes of Scottish sunshine in November, but the result is roughly the same.
We brought the printing frame back to our shady loading bay, where we could safely remove the paper, wash out all the remaining light sensitive silver and ‘fix’ the image with a strong salt bath, or sodium thiosulphate, commonly called ‘hypo’. Talbot’s original experiments used various kinds of salts, which gave slightly different colours, however the use of hypo, recommended to him by his friend John Herschel, leaves a more permanent image which would have been used for all images in the Pencil of Nature.
The keen observer will notice a distinct difference between Plate VII and our photogenic drawings; Plate VII appears in positive whereas ours is in negative. Talbot goes on to explain this slightly confusing relationship in Plate XX where he shows a ‘negative’ image. But to briefly clarify, one would create a negative image such as ours first, then following the exact same process use the first photogenic drawing/negative image to create a print such as is shown above thus appearing in positive.
This negative-positive relationship was at the core of photography for over 150 years ending with what most of us remember as 35mm roll film. However, before modern film, and predominantly throughout the second half of the 19th century, there was a wave of innovations and advancements in ‘photography’ exploiting the innate qualities of glass, collodion and gelatine, each giving new and distinct properties to the medium and the artist, but it all started with Talbot’s chemistry experiments on a simple piece of paper.
As this is the first example of a negative image that has been introduced into this work, it may be necessary to explain, in a few words, what is meant by that expression, and wherein the difference consists.
The ordinary effect of light upon white sensitive paper is to blacken it. If therefore any object, as a leaf for instance, be laid upon the paper, this, by intercepting the action of the light, preserves the whiteness of the paper beneath it, and accordingly when it is removed there appears the form or shadow of the leaf marked out in white upon the blackened paper; and since shadows are usually dark, and this is the reverse, it is called in the language of photography a negative image.
– William Henry Fox Talbot, Plate XX, in The Pencil of Nature
– Rachel Nordstrom
Photographic Research & Preservation Officer