This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
A weight of the smallest particle that can exist. Molecular weight is ascertained by adding together the weights of all the atoms of the various elements, which have united to form the molecule of the chemical.
The smallest quantity of two or more atoms forming a chemical compound.
A picture in one color.
A viscous substance or adhesive used for mounting prints.
Double mounting is the placing of a print on a secondary mount, which latter is attached to the real mount or base. The secondary mount should be of a different shade, yet of the same color, as the base.
Multiple mounting calls for the use of more than two tints of paper or light cardboard on which to place the print. Each successive layer underneath the print is a trifle larger than the preceding one. The photographer's taste and skill are brought into play when using this method of mounting, as it is by the artistic combination of various tints and shades that the value of the picture will be enhanced, rather than detracted from.
A specially prepared tissue used for dry mounting. Mounts, Sizes of.
1 5/8x3 1/8.
A term given to various forms of adhesives composed of gums, dextrine, etc.
(See Mounting Multiple.)
(See Ammonium Chloride.)
(See Calcium Chloride.)
(See Acid Hydrochloric.)
Benzin; Petroleum Ether. Light, transparent, colorless, volatile liquid. Soluble in ether, oils and carbon disulphide. Used extensively in dissolving various resins, also in the manufacture of varnishes.
Naphtha, Coal. (See Benzene.)
Mineral Naphtha is another name for petroleum oil or kerosene. Use: It is a solvent for India rubber, sulphur, phosphorous, camphor, iodine and a large majority of the resins, wax, fats, etc. It is also employed for illuminating purposes. Mixes with alcohol and oils, but not with water.
A name given to impure methylic alcohol. Naphthol, Green.
Green powder. Soluble in water, giving a yellowish-green color. Used in color photography.