These millions of little C. de V' now being turned out in all parts of the world, were printed from Wet Plates, sometimes called the Collodion Process; and before we can understand and appreciate the great difficulties of working it, a short and simple explanation of its chemistry is necessary.
It was a extension of Fox Talbot's process which consisted of sensitising a sheet of paper in nitrate of silver, exposing it in the camera and then developing up a negative image. From this paper negative any number of prints could be made. Paper is, however, only partly transparent, and when printing through it, some of the opaque grain and fibre and structure of the paper is printed on to the picture, giving it a rather course and mottled print.
After a century of impressionism in Art, these old Talbotypes are now considered very charming, but in their day they were thought to be crude. So there was prolonged research to find a method of sensitising some completely transparent substance that would give a clear negative from which perfectly detailed pictures could be printed.
Glass was the obvious medium if it could be coated with a transparent film that would absorb and hold the liquid solution of silver. Eventually it was discovered by a pupil of Faraday's that a film of collodion was adequate for the purpose. Collodion is also known as a gun-cotton, and is a high explosive. In practice it was usually made by dissolving cotton-wool or wadding in nitric and sulphuric acids to form a thick creamy emulsion. This emulsion was easily coated on to a glass plate to which it adhered like paint. It was as transparent as the glass itself, and it was not affected by any of the acids or chemicals used in the subsequent processes of developing and fixing and washing; nor would it swell, stretch or perish.
In these early day every photographer was his own manufacturer. He purchased sheet glass from the ironmonger, cut it to size and polished it. He made up his collodion, coated it on his plates, and set them in racks to dry. When he was ready to take a picture, he threw a few crystals of nitrate of silver into a dish, dissolved them with a cupful of water, placed one of the collodion-coated plates in this sensitising solution for a few seconds, then inserted the plate in its carrier, took it to the camera, exposed it on his subject for five seconds- and returned it to the dark-room and developed it immediately while it was wet; for this sensitised plate that was used for practically all of the photography done in the world between 1855 and 1880 (whether in a studio or away from it), had an effective life of only two or three minutes. It had to be used while it was wet. The moment it dried it was useless.
Thousands of photographers and many scientists struggled with this problem for a quarter of a century before they solved it.
Throughout tis long period of the wet plate, the camera was chained to a dark-room. When a photographer left his studio for a assignment around the corner, or on a distant mountain peak, he had to take a dark-room and all his chemicals and equipment with him. The whole business was so difficult that few studios undertook any outside work at all. Fortunately, however, there are always to be found the types of men who glory in difficulties; and there were one or two of these in our major towns who devoted themselves entirely to outdoor photography. These men used tents and horse drawn vehicles of many varieties. There were large caravans and there were two horse tinkers with trailers attached.
From1850 onwards, governments and corporations were giving commissions to wet-plate photographers to go into distant places and bring back pictures of the countryside.
Amongst the world's famous workers to this difficult process were the Englishman Roger Fenton, First Secretary of the Royal Photographic Society, who took his great cameras to the Crimean War; and Mathew Brady, a fashionable society photographer of New York, who left his studio to take thousands of pictures of the American Civil war. That was the bloodiest war in history up to its time.
Albums of both these men's pictures are in our historical societies. They should have served to outlaw war forever.
Great as these men were I believe that two Australians, Nettleton in Victoria, and Merlin in New South Wales, did far more sustained and equally important work. We shall tell the fantastic story of Merlin in another chapter, as he comes later in the sixties.