Photography

Some philosophers contend that to the existence of light alone we owe the beautiful effects produced by the Photogenic art, while others give sufficient reasons for doubting the correctness of the assumption. That the results are effected by a principle associated with light and not by the luminous principle itself, is the most probable conclusion. The importance of a knowledge of this fact becomes most essential in practice, as will presently be seen. To this principle Mr. Hunt gives the name of ENERGIA.

Having before noticed the fact that some advances had been made towards taking Daguerreotypes in color, by means of solar rays, and expressed the hope that the day was not far distant when this might be accomplished, I here subjoin Mr. Hunt's remarks on this subject.

There are very few who may not be capable of practising the Photographic art, either on paper, or metalic plates--but, like all other professions, some are more clever in its various processes than others.

Before taking leave of the subject of photogenic drawing, I must mention one or two facts, which may be of essential service to operators.

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.

This subject is worthy the attention of every operator. The following process is so plain and easy of trial that any Daguerreotypist can try it. This is as given by Mr. James Campbell, and was published in Humphrey's Journal of the Daguerreotype and Photographic Arts, vol. 5, page 11. Mr. Campbell has done much to further the process announced by M. Neipce, and his experiments have proved highly successful.

The following is submitted as worthy of trial:

Cyanide of Potassium.--This important article is worthy the undivided attention of every Daguerreotypist. I here give Mr. Smee's process for its preparation. This is from that author's work entitled, "Electro Metallurgy," American edition:

I have produced some interesting specimens of the Daguerreotypic art, by exposing in the camera only a portion of the sensitive plate to the action of light. When on the exposed portion an image is formed, then taking the tablet into the dark room, change ends and expose the sensitive portion, and produce another image, developing as usual. This plan is adapted for taking likenesses for lockets. Two images can be presented as sitting side by side, by covering half the plate with black paper, and exposing as before.

Hyposulphite of Soda.--This salt forms one of the important chemicals for the Daguerreotype operator. Its application to this art is of an interesting nature. It is used to dissolve the sensitive salt of silver which remains unchanged during the exposure in the camera. It has the property of readily dissolving the chloride, bromide and iodide of silver. It should be pure and free from sulphuret of sodium; should this last be present, it will cause brown spots of sulphurated silver upon the Daguerreotype impression.