Photography

The entire Daguerreotype process is comprised in seven distinct operations; viz:

1.--Cleaning and polishing the plate.

2.--Applying the sensitive coating.

3--Submitting the plate to the action of light in the camera.

4.--Bringing out the picture; in other words rendering it visible.

5.--Fixing the image, or making it permanent--so that the light may no longer act upon it.

The Roman Astronomers state that they have procured Daguerreotype impressions of the Nebula of the sword of Orion.

The process of taking Daguerreotype pictures differs very materially from all others of the photographic art, inasmuch as the production of the image is effected upon plates of copper coated with silver. The silver employed should be as pure as possible; the thickness of the plate is of little consequence, provided there be sufficient silver to bear the cleaning and polishing--is free from copper spots, is susceptible of a high polish, an exquisitely sensitive coating and a pleasing tone. These qualities are possessed to an eminent degree by the French plates.

Nearly, if not quite all the various colors used in painting may be made from the five primitive colors, black, white, blue, red and yellow, but for the Daguerrean artist it would be the best policy to obtain such as are required by their art already prepared. In a majority of cases, the following will be found sufficient, viz.

Mr. Hunt describes a process, discovered by himself by which the Daguerrean art may be applied to paper. His description is as follows:--

The last number (for March, 1849) of the London Art-Journal, gives the following description of a recent improvement in Photographic Manipulation, and as I am desirous of furnishing everything new in the art, I stop the press to add it, entire, to my work.

Remarks on the Accelerating substances Used in the Daguerreotype.--I have now arrived at a point in this work, where the eye of the Daguerreotype public will intently search for something new. This search will prove in vain, at least so far as regards those who have enjoyed and embraced the opportunities for studying the principles of our art.

Regarding specks from bad water, I would remark that gilding should be made only with distilled water. Thus made, it produces very little deposit, even by long keeping. It therefore preserves its original strength, and works with great uniformity.

Hydrate of Lime.--The operation by which water is combined with lime is called slaking. Take a piece of quick lime, common lime used in mortar, and immerse it in warm water for about fifteen seconds; then place it in an iron or tin vessel. It will soon begin to swell, evolving a great deal of heat and emitting steam, and soon falls into a fine powder, hydrate of lime. This should be well stirred and allowed to cool, and then bottled in order to prevent it from giving off the hydrate and recovering the carbonic acid from the atmosphere.

The following is from Humphrey's Journal, vol. 5, and from the pen of Dr. WM. HARRINGTON, one of the most able writers upon the subject of the Daguerreotype in this country: