Any tendency of a stove or other electric device to give people a shock when being used should be taken as a warning to have the device examined by an expert and the trouble corrected. Have the wires repaired as soon as the insulation breaks or burns off. Uninsulated wires, such as cables and cords, are unsafe. CHAPTER V ALCOHOL, ACETYLENE, AND CANNED HEAT =42. Alcohol Stoves.= Alcohol stoves are made only in small sizes for light housekeeping. There are three general types of these--those which burn with a wick, those which generate gas, and those which permit the alcohol to burn off of the top surface of the container. Alcohol does not produce much smoke in burning, even when no provision is made for mixing air with it. The ordinary alcohol lamp, having a wick, may be used as a heating stove. Stoves with wicks draw the alcohol up by capillary attraction to the point of ignition, and the metal jacket about the wick prevents the fire burning back into the bowl containing the alcohol. The char from the top of the wick must be brushed off from time to time. No other care is needed for these stoves or lamps. Some of them are provided with devices for checking the burning of the alcohol in order to regulate the heat. This is desirable since a small flame of alcohol produces much heat. Extinguish the fire by covering the wick with a metal cup. =43. Vapor Stoves.= Alcohol vapor stoves which generate gas hold the alcohol in a tank slightly raised above the level of the burner. A pipe leads from this to the burner, where a small stream of alcohol is permitted to enter when the valve is open. When starting these stoves, the valve is first opened and enough alcohol allowed to flow out to fill a cup which is below the burner. This generally holds about a tablespoonful of alcohol. When the cup is full, the valve is closed and the alcohol in the cup ignited. This heats the burner enough to vaporize the alcohol. When the burner is heated, open the valve and ignite the gas. If all the alcohol is not vaporized, the burner has not been heated hot enough. Close the valve until all the alcohol in the cup is burnt. =44. Wickless Stoves.= Wickless alcohol stoves are used commonly on chafing dishes. The burner of one type consists of a metal dish packed with a porous material which is non-inflammable, but a good conductor of liquids by capillary attraction, and the top is covered over by a wire screen. The alcohol is poured into the dish. The packing and screen prevent air from entering the bowl with sufficient rapidity to let the fire burn below the screen so the flame stays above it, burning off any alcohol which is conducted to the surface.