Preparing biographies

These stereoscopic transparencies are taken by a modification of Taupenot’s collodion albumen process. The plates are prepared as follows:- After throroughly cleaning the plate it is to be coated with collodion in the usual manner, taking care that the collodion used is of the kind known as ‘short’ or ‘powdery’. The plate is then well washed with plain water, till all streaky lines are removed, and the surface appears uniformly wetted. Then stand it up to drain by one corner for about a minute, after which pour on the albumen: pour this on and off three or four times, then stand up as before to dry. This time it must be dried thoroughly; it is best to use heat for this purpose.
‘Plates prepared in this manner will last an indefinite period. When required for use they are to be sensitized in a 40 grain bath of nitrate of silver, containing half a dram of glacial acetic acid to 1 oz. of both solutions; then well washed, and when dry are ready to receive the impression.
‘The plate is exposed in exactly the same manner as the paper in taking an ordinary print, the only difference being the time of exposure, about 3 to 6 seconds in diffused light being sufficient. I have frequently printed these pictures by artificial light, the exposure being then about 10 minutes..
‘To develope the picture, lay it face upwards on a leveling stand, taking care that it stands perfectly level, and cover the surface with a saturated solution of gallic acid; pour this off, and add 2 or 3 drops of a 30 grain solution of aceto nitrate solution; return it to the glass; do this two or three times, and finally let it remain on the plate. The picture will be fully developed in from 10 to 15 minutes.
‘When fully developed wash with water, and fix with a solution of hypo; the strength of which is of little importance.
‘The picture is now of a disagreeable greenish tone, but this is very easily got rid of; it is only necessary to put it in an ordinary toning bath, and in a short time almost any desired shade can be obtained.
‘The most important part of this process is perhaps the preparation of the albumen: this is done as follows:-
‘Take the whites of three eggs.
‘Glacial acetic acid 8 drops
‘Water half oz
‘Sugar quarter oz
‘These are to be well mixed together, and then left to rest for about 10 minutes; at the end of which time a thick scum will be found on the surface, which must be removed. Then add 12 grains of iodide of calcium (no other iodide will answer so well) dissolved in 2 drams of water, filter through paper, and it will be ready for use.
‘I may mention, in justice to myself, that I have every reason to believe I was the first to use this process; it is in very extensive use in London for the production of magis lantern slides, for which I first used it; and is I believe the only way in which either those or stereoscopic slides can be produced in any way approaching the French ones.’^[3]

1. Λ The Englishman, 24 February 1859. 
     
   
2. Λ Cited in Christopher Pinney, Camera Indica, p. 232. 
     
   
3. Λ The Englishman, 28 May 1859. 
     
   
4. Λ idem. 
     
   
5. Λ Journal of the Bengal Photographic Society, vol. 1, no. 1, 1 May 1862, p. 6.