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it is called chlorine, from the Greek word meaning green. 

 Now this gas is one of the constituents of common salt. 

 You will see it issuing from the vessel where the acid and 

 black oxide of manganese were mixed. If I dip a clean 

 platinum wire into this solution of common salt and then 

 thrust it into this blue flame of the spirit lamp, the flame 

 is at once colored a deep orange. You see at once that 

 common salt must be the substance used to produce the 

 yellow color in fireworks. In the neighborhood of the 

 ocean the air becomes filled with fine particles of salt, 

 which it deposits abundantly on all objects it comes near ; 

 on the leaves of trees, on the grass, on our houses and on 

 our garments. As you see, I have but to brush my coat 

 sleeve and the flame of the spirit lamp is colored a deep 

 yellow. From this bottle, which is nearly filled with 

 naphtha, I take a piece of dark gray substance which is 

 soft as putty, and which, when cut, shows a bright metal- 

 lic surface, which looks like freshly cut lead. I throw a 

 piece of it upon water and you see it kindles and is 

 quickly burned up. I find that this water, which was 

 pure before, is now a weak solution of soda lye, such as 

 is used for cleansing and for making hard soap. I dip 

 the platinum wire into this solution and then thrust it 

 into the flame, and you see again the orange colored light. 

 A very minute portion of this substance when put into a 

 flame can be seen by the help of the spectroscope. One 

 fifty millionth of a grain is easily detected by means of 

 this most delicate instrument. This substance is called 

 sodium. It is the other constituent of common salt. 

 These two elements, chlorine and sodium, give salt the 

 name chloride of sodium. We thus see that common salt 

 is a compound of a green gas with a bright glistening 

 metal. 



But there are many other substances in sea water. A 



