Water Color

Water color is color pigment dissolved in water and used for the coloring or tinting of photographs, lantern-slides, etc., as well as for painting what is known as water-color pictures.

Water Distilled

The purest form of water is obtained by converting water into a gas and then condensing it again to water. By this process all of the mineral and solid impurities are left behind. Distilled water should be used for mixing all photographic solutions, for it is only by its use that one can be absolutely certain of the most perfect results.

Water, Hard. (See Water.)

Water, Soft. (See Water.)

Alkalies

If red litmus paper is immersed in the water and allowed to remain one-half hour and it does not change color, alkalies are not present.

Carbonic Acid

Add an equal part of lime water to the water being tested. If carbonic acid is present a precipitate will result, and upon the addition of hydrochloric acid the precipitate will effervesce.

Chlorides

If a solution of silver nitrate gives a precipitate in water chlorides are present.

Hard Water

Dissolve good soap in alcohol; drop a few drops in a glass of water. If the water becomes milky it is hard, while if it remains clear it is soft.

Iron

Boil nut galls and add to the water. If iron is present the water will turn to a gray color. Add a pinch of red prussiate of potash; if it turns blue, iron is present.

Lime

Place two drops of strong oxalic acid solution in a glass of water. If it turns the water milky, lime is present. When lime is present ammonium oxalate will give a precipitate.

General Purities

In half a tumbler of water place a couple drops of dilute sulphuric acid and enough permanganate of potash to tinge it to a faint rose color. Cover the glass with a saucer or glass plate. If after 15 or 20 minutes the pink tinge still remains visible, the water is all right for general photographic use, yet distilled water should be used, if possible, in mixing all solutions.

Organic Matter

Organic matter is present when permanganate does not give a permanent pink tint to the water.

Sewage Gases

Into a wide-mouthed bottle pour about one-half pint of water. Close it with a stopper or the palm of the hand, and shake violently up and down. Should an offensive odor be then detected, the water is contaminated with sewage gas.

Sodium Chloride

With distilled water make a solution of silver nitrate. Carefully clean a glass and put a little of the solution in it, being sure that the solution remains transparent. Pour in some of the water to be tested. If a strong milkiness appears which is not cleared by the addition of a little diluted nitric acid, the water contains much sodium chloride.

Sulphuric Acid

If the addition of barium chloride gives a precipitate, sulphuric acid is present.