794. Hammer's Dry Powder Developer

Hammer's Dry Powder Developer. (For the amateur.) (Factor 8.) Is compounded with accuracy from the best of chemicals insuring good results to the user.

795. The only caution that is necessary is for the user to be sure that both powders are entirely dissolved; then if the plate has the correct exposure (or near it) a good negative will result.

796 We do not advocate this developer in preference to those that may be prepared from our published formulae, if good chemicals are used; but for those who do not wish to make up stock solutions, or when going on a trip they wish to carry the developer in a form that shall not cause damage to other goods in case of breakage, this is just the developer that will fill the bill for this purpose, as a trial will convince you. There are none better and we have found none as good (in this class).

797. This developer is enclosed in sealed glass tubes, six tubes in a box. Each tube will make from five to seven ounces of developer. (The more water used the softer the effect.)

798. Negatives

Negatives. Negatives suitable for all the different printing processes - carbon, platinum, albumen, collodion, gelatine, etc., - may be successfully and easily made on the Hammer Plates by a slight modification of the developing solutions.

799. Washing After Development

Washing After Development. In all cases it is desirable to wash the plate for at least two minutes before fixing it.

800. Fixing

Fixing. The plain fixing bath is a solution of hyposulphite of soda, of a strength of about five (5) or six (6) ounces to the pint of water. A fully saturated solution diluted with an equal quantity of water is of about this strength. The plate should be left in the fixing bath for several minutes after it appears to be cleared; as long as it took to fix would not be too much. Neglect of this precaution may lead to the formation of insoluble compounds in the film, which, although not visible at first, may in time result in stains or even total decay of the negative. Commercial hypo-sulphite of soda usually contains foreign matter, which, if allowed to remain in the solution, will cause spots on the negative. Filter before use. If the regular fixing bath is too strong and not stirred before use, it will at times cause parallel lines on the negatives that were fixed in grooved fixing boxes.

A cool fixing bath can be prepared by dissolving a fresh lot of hypo for each batch of plates. This is of benefit during the hot weather.

801. Acid - Fixing Bath

Acid - Fixing Bath. Owing to the quality of the water in some localities, some workmen prefer an acid-fixing bath. The following is good and remains clear (mix in order given):

Water (about)

120 ounces

Sulphuric Acid

............. 3 drams

Sulphite of Soda..............

............. 4 ounces

When dissolved, add:

Hypo- sulphite of soda

2 pounds

Water to make...............

160 ounces