History and practise of photogenic drawing on the true principles of the Daguerréotype. With the new method of dioramic painting; secrets purchased by the French government, and by their command published for the benefit of the arts and manufactures / by L.J.M. Daguerre. Translated from the original by J.S. Memes.

  • Louis Daguerre
Date:
1839
Catalogue details

Licence: Public Domain Mark

Credit: History and practise of photogenic drawing on the true principles of the Daguerréotype. With the new method of dioramic painting; secrets purchased by the French government, and by their command published for the benefit of the arts and manufactures / by L.J.M. Daguerre. Translated from the original by J.S. Memes. Source: Wellcome Collection.

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    camera the plate gives no indication of the images traced upon it, our next operation must be to evoke these hidden forms.* Provide a vessel of tinned copper or sheet-iron larger than your tablet, and having all round a ledge or border 50 mille- metres in depth. Fill this three-quarters full with oil of petroleum ; fix your tablet by the back to a piece of wood which completely covers the vessel of oil, placing it so that the tablet, face downwards, is over but not touching the oil. In this position the petroleum evaporating, penetrates entirely the coating of the tablet in those places on which the action of the light has been feeble, that is, in the portions of the picture corresponding to the shadows, imparting to them a transparency, as if nothing were there : those points, on the contrary, upon which the light has acted with all its intensity, and which consequently express the lights on the natural objects represented, remain unchanged, because they resist the action of the petroleum. In this manner, the whole harmony and gradation of tints are brought out by the varied action of the vapour upon the coating of the tablet, in proportion as that has received the impressions of light. The design must be examined from time to time, and withdrawn as soon as a vigorous effect is obtained. For, in urging the action too far, even the strongest lights will be attacked by the vaporization and will disappear, to the ruin of the piece. The picture being finished, a glass is placed over it as a protection against the dust, which is first to be blown away if any has fallen upon the tablet during the operation. Placing the designs under glass will also preserve the silver plating from being injured by the vapours which blacken or corrode the metal. * [There seems to be here a contradiction between Daguerre’s remarks on Niepce’s process and the description of his own improve- ments. See M. Daguerre’s note, p. 35,—Translator.]