To test kerosene, put a thermometer into a cup partially filled with cold water, and add boiling water until the mercury stands at 130 degrees Fahrenheit. Then take out the thermometer and pour two teaspoonfuls of kerosene into the cup and pass over it the flame of a candle. If the oil ignites, it is unsafe. In order to prevent the flame from running down into the lamp and causing an explosion, the wick should be soft, filling the burner completely. The highest efficiency in the form of illumination is obtained by round burners, especially those in lamps which admit air to the inside of the wick and so induce the largest possible amount of combustion. Such a lamp produces quite a high degree of heat, and will answer the purpose of an oil-stove in a small room. Contrary to the popular idea, wicks should be carefully trimmed with scissors rather than with a match or other instrument. In extinguishing a lamp one should first turn down the wick and blow across the chimney, never down the chimney. Owing to the fact that the wick is constantly bringing up oil by capillary attraction, whether it is lighted or unlighted, lamps in which the wicks have not been cared are kept continually greasy. In fact, a lamp that is greasy or that gives out a bad odor is one that has not been properly cared. With due attention, lamps are as clean and handy a means of illumination as any other form. Candles, that are now used chiefly for decorative purposes, may still be practically employed for carrying light about the house. The danger from a falling candle carried by a child up to bed is not nearly so great as that which may result from either spilt oil from a broken lamp or the cutting glass of its chimney.