TO ASCERTAIN THE QUALITY OF WATER.
The proper way to ascertain with accuracy the character of water, is to send specimens to a competent analytical chemist for quantitative analysis. But, as few railroad companies will incur the expense of having the water of the water stations systematically tested, master mechanics may, by a little labor, study, and practice, learn to make tests for themselves that will indicate near enough for practical purposes the character of each water station supply.
As master mechanics are the railroad officials most directly interested in the kind of water supplied for locomotive use, they ought to have direct control of all the water stations on the roads where they are in charge.
APPLIANCES NEEDED IN TESTING WATER.
The chemical apparatus needed for the examination of well-water are, a balance that will weigh accurately to half a grain; an oil stove for evaporative purposes; a few pint porcelain evaporating dishes; a sand-bath, which can be made from a piece of sheet-copper; a dozen test tubes; half a dozen vials to hold solutions of chemically pure chemicals; some pieces of glass tubing; a small mortar and pestle; a supply of filtering-paper; and the vessels needed for measuring accurately. For the solution of the chemical re-agents to be used, a supply of distilled water is necessary; and water of this kind is also necessary to make comparisons with. A piece of pure crystalline ice, when melted, will generally produce water pure enough for experimental purposes.
PREPARING FOR THE EXPERIMENTS.
In bringing in water for examination, it is best to have it drawn from the water-tank into a perfectly clean jug, which should be corked and labeled. Weigh an evaporating dish, noting down the exact weight, and on a sand-bath evaporate one quart or half a gallon of the water to be inspected. When the dish becomes dry, rub off all dust that may be adhering to the bottom, and weigh the dish. The added weight will indicate approximately the total amount of solid matter in the water. Note that down, and every other detail of the experiments.
LIME HELD IN SOLUTION BY FREE CARBONIC ACID.
Sometimes a large quantity of bicarbonate of lime is held in solution by free carbonic acid, which escapes as soon as the water is boiled, leaving the lime to subside in the form of mud. Water of this kind may appear very hard, yet not be very objectionable for boiler use; since the deposit can be blown out if the blow-off cock is used freely. To test this, boil a pint of water for two or three minutes in a perfectly clean dish, then pass it through a filter paper that has been previously dried and weighed. When the operation is finished, dry and weigh the filter paper again; and the added weight will indicate the amount of solid matter held in solution by free carbonic acid gas.