In coloring the eyes, the artist will of course be guided by nature, observing a very delicate touch in laying on the colors, so as to preserve as much transparency as possible. A slight touch of blue--ultramarine would be best if it would adhere to the Daguerreotype plate--in the whites of the eye near the iris, will produce a good effect. In coloring the heads of men it will be necessary to use the darker tints with more freedom, according to the complexion of the sitter. For women, the warmer tints should predominate, and in order to give that transparency so universal with the softer sex--and which gives so much loveliness and beauty to the face--a little white may be judiciously intermingled with the red tints about the lighter portions of the face. In taking a picture of a lady with light or auburn hair, by the Daguerrean process, much of the beauty of the face is destroyed, on account of the imperfect manner in which light conveys the image of light objects to the spectrum of the camera. This may be obviated in some measure by proper coloring. To do this, touch the shaded parts with burnt sienna and bistre, filling up the lighter portions with yellow ochre, delicate touches of burnt sienna, and in those parts which naturally have a bluish tint, add very delicate touches of purple--so delicate in fact as hardly to be perceived. The roots of the hair at the forehead should also be touched with blue, and the eyebrows near the temples made of a pinkish tint. The chin of a woman is nearly of the same color as the cheeks in the most glowing parts. In men it is stronger, and of a bluish tint, in order to produce the effect given by the beard. In portraits of women--the middle tints on the side of the light, which are perceived on the bosom and arms, are made of a slight mixture of ochre, blue and lake, (or carmine), to which add, on the shaded sides, ochre, bistre and purple, the latter in the darker parts. The tints of the hands should be the same as the other parts of the flesh, the ends of the fingers being a little pinkish and the nails of a violet hue. If any portion of the fleshy parts is shaded by portions of the dress, or by the position of the hand, this shade should be colored with umber mixed with purple. TO COLOR THE DRAPERY.--Violet Velvet--Use purple made of Prussian blue and carmine, touching up the shaded parts with indigo blue. Green Velvet--Mix Prussian blue and red-orpiment, shade with purple, and touch up the lights with a little white. Red Velvet--Mix a very little brown with carmine, shading with purple, marking the lights in the strongest parts with pure carmine, and touch the most brilliant slightly with white. White Feathers--May be improved by delicately touching the shaded parts with a little blue mixed with white. White muslin, linen, lace, satin, silk, etc., may also be colored in the same way, being careful not to lay the color on too heavily.