FUEL AND LIGHT 289 



Alcohol. Alcohol is used as a fuel for spirit lamps by dentists 

 and by students in laboratories where gas cannot be obtained. 

 It is also used in heating chafing dishes. Recent experimenters 

 claim that it can also be satisfactorily used for cooking purposes 

 in countries where excessive internal revenue taxes are not levied 

 upon it. 



There are two kinds of alcohol that can be used for this purpose, 

 one known as methyl, or wood, alcohol, and a second one called 

 ethyl, or grain, alcohol. 



Wood alcohol is obtained by the dry or destructive distillation of 

 wood. It was discovered by Taylor in 1812, and he gave to it the 

 name of wood spirit. Wood alcohol is poisonous and so no restric- 

 tions are usually placed upon its sale for fuel. It burns with a pale 

 blue flame and produces a fair amount of heat. 



Ethyl alcohol is obtained by distilling fermented liquors, such as 

 wine, the fermented juice of sugar beets, malted corn, barley, rye, 

 and other grain. In England and France ethyl alcohol employed 

 for industrial purposes is exempted from taxation to a large extent 

 when it has been treated with one tenth per cent of wood alcohol, 

 resin, and certain mineral oils. In this state it is known as de- 

 natured alcohol, and it cannot be used as a beverage. Provision 

 has been made in the United States for the sale of denatured al- 

 cohol at greatly reduced rates. It is believed that the production 

 and use of denatured alcohol will give renewed impetus to the 

 sugar beet industry and make it much more profitable. 



Candles. One of our earliest means of illumination was by 

 means of ordinary candles. They give a weak flickering flame 

 and afford a very poor light, but for a long time there was no 

 available substitute and they were in general use. Candles are 

 made of tallow, wax, or spermaceti. 



Electricity. In cities electricity is found to be a very satis- 

 factory and economical means of illumination. The common 

 incandescent lamp was devised by Thomas Edison in 1879 and is 

 suitable for electric lighting indoors. It consists of an air-tight 

 bulb in which is fitted a carbonized filament in the form of a loop. 

 When a current of electricity is passed through this carbonized 

 filament, it becomes hot and gives off a bright light. 



For street lighting what is known as the arc light is used. It 



PRAC. AGRICUL. 19 



