If 



Mr. Chevallier's plan is to trace on the glass which is intended 

 to protect it, the outline of the picture, and then to tint it with 

 the colours used for painting the dissolving views, so as to corres- 

 pond with the picture underneath. When dry, the tracing may be 

 effaced, the glass fixed, and the picture will then appear through, 

 something in the style of a coloured lithograph. 



M. Leotard de Seuze covers the plate with a transparent mem- 

 brane, or vegetable paper, which he attaches by a solution of gum 

 or size, heated in a water bath ; on this membrane he applies 

 colours, mixed with spirits of wine and gum, or with white varnish 

 and alum.* 



Mr. Page, whose new method ofixing the Daguerreotype proofs 

 is given page 15, has thrown out the following suggestions on the 

 subject of Coloring : 



As copper assumes various colours, according to the depth of 

 oxidation upon its surface, it follows, that if a thicker coating than 

 the first mentioned can be put upon the plate, without impairing 

 the impression, various colours may be obtained during the fixation. 

 It is impossible for me to give any definite rules concerning this 

 last process ; but I will state, in a general way, that my best results 

 were obtained by giving the plate such a coating of copper as to 

 change the tone of the picture, that is, give it a coppery colour, and 

 then heating it over a spirit lamp until it assumes the colour desired. 

 I have now an exposed picture treated in this way at the same time 

 with the two above mentioned, and it remains unchanged. It is of 

 a beautiful green colour, and the impression has not suffered in the 

 least by the oxidation. Should this process be perfected, so as to 

 render it generally available, it will be greatly superior to the 

 present inartistical mode of stippling dry colours upon the impres- 

 sion ; for the colour here is due to the surface of the picture itself. 

 For pure landscapes, it has a pleasing effect, and by adopting some 

 of the recent inventions for stopping out the deposit of copper, the 

 green colour may be had wherever desired. In some pictures, a 

 curious variety of colours is obtained, owing to the varying thick- 

 ness of the deposit of copper, which is governed by the thickness 

 of the deposit of mercury forming the picture. In one instance, 

 a clear and beautiful ruby colour was produced, limited, in a well- 

 defined manner, to the drapery, while all other parts were green. 



These three receipts are condensed from M. Lerebonr's excellent Traite de 

 Photographic, from which other valuable suggestions are taken. 



B 



