THE DAGUERREOTYPE PROCESS.

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.

Having already enumerated the various processes--and the apparatus

necessary for the manipulation, I will here give a list of the

chemicals to be used, and then proceed to explain them more fully. The

requisite chemicals are--

NITRIC ACID, ROUGE,

DRY IODINE, MERCURY,

DRYING POWDER, HYPOSULPHITE OF SODA,

CYANIDE OF POTASSIUM, CHLORIDE OF GOLD; OR

ROTTENSTONE, HYPOSULPHITE OF GOLD.

TRIPOLI, CHLORIDE OF SILVER.

CHLORIDE OF IODINE, } their compounds, or other

BROMINE } accelerating mixtures.

FIRST OPERATION.--Cleaning and polishing the plate.--For this purpose

the operator will require the--

Plate Blocks,

The History and Practice of the Art of Photography · 第 23 / 52 题