Vulcanized Rubber Ebonite. Vulcanite

A hard, black, ebony-like substance, formed by combining sulphur and India rubber. Used for developing dishes, dippers, in the collodion process, slides for plate-holders, etc.

Edinol

A good developer for securing soft portrait negatives and owing to the fact that it produces softness, it is especially available for short exposures. A good snap-shot formula is:

Edinol............................................................

1 drm.

Acetone-Sulphite..........................................

187 grs.

Potassium Carbonate....................................

1 1/3 ozs.

Potassium Bromide......................................

27 grs.

Water ...............................

14 ozs.

Efflorescence

A chemical term applied to the formation of loose, fine crystals on the surface of a porous substance. Caused by gradual decomposition when exposed to air.

Eikonogen

NH2C10H5(OH)SO3Na + 2 1/2H2O - II.

White powder; strong reducing power on silver salts. A developing agent giving soft, delicate negatives of good color. Does not stain. May be used in conjunction with pyro and other developers. As it is only slightly soluble in water it is necessary that it be mixed up in bulk, i. e., not in concentrated solutions. Different temperatures alter the strength of eikonogen. A good formula for soft results is:

Eikonogen..............................................

150 grs.

Sodium Sulphite.....................................

300 grs.

Sodium Carbonate..................................

300 grs.

Water....................................................

13 1/2 ozs.

Potassium Bromide (10% Sol.).................

2 or 3 drops.

Element

An element is a substance which consists of one kind of matter only, i. e., a substance which resists all efforts to divide it into any simpler form. Ex. Gold, silver, sodium, etc.

Hypo Eliminator

(See Hypo Eliminator.)

Emery

A dark-colored, hard mineral. In fine powder it is used for grinding and polishing glass, metal, etc.

Emulsion

The coating on plates and paper which is sensitive to light. It is a mixture composed of some viscous substance, such as gelatin or collodion, sensitive silver salts, etc.

Enameling

The process of giving a high gloss to prints; usually termed squeegeeing, which is accomplished by placing the print on a highly polished glass or ferrotype plate.