342 KANSAS CITY REVIEW OF SCIENCE. 



till distributed. The process of condensing, purifying, etc., is essentially the 

 same as that employed for coal gas, the impurities being about the same, with the 

 exception of ammonia, which is seldom found in water gas. 



Water gas as it comes from the gasogens, and before it is enriched with 

 naphtha vapor, has a specific gravity about one-half that of atmospheric air, with 

 quite a strong odor, and it burns with a non-luminous flame, producing an in- 

 tense heat. It consists of about equal parts of carbonic oxide and hydrogen, 

 some marsh gas, carbonic acid, and various other impurities from the coal. 



After being enriched and purified it has still a strong odor, and has a specific 

 gravity of about 0.66 compared with air. Its illuminating power differs with the 

 amount of naphtha used, generally ranging from twenty-five to thirty candles. It 

 is more combustible than coal gas, requiring less oxygen to burn it, and there- 

 fore should not have as deleterious an effect upon the atmosphere of a room in 

 which it is burned. 



When a mixture of water gas and air is exploded, the explosion seems to 

 take place more slowly than in the case of coal gas and air, exerting a steadier 

 pressure with less shock, as is shown by windows being blown out without break- 

 ing the glass. 



The following is an analysis made by Mr. E. G. Love, city gas tester of the 

 gas furnished by the Municipal company of New York City : — 



Hydrogen 26.25 



Marsh Gas 2^.91 



Carbonic Oxide . . 27.12 



Illuminants i5-8o 



Nitrogen 1.92 



It is very generally known that water gas can be made more cheaply than 

 coal gas, although both sell for the same price, because their luminous powers are 

 about the same. When electricity shall displace gas for illumination, there will 

 still be a field for water gas as fuel. As the enriching process can be omitted, 

 the price can be reduced so that it will be as cheap as coal. — Boston Journal of 

 Chetnistry. 



CHEMICAL PARADOXES. 



We are accustomed to associate the idea of combustibihty with paper. If it 

 be wrapped tightly around a metallic rod it can be held in a gas flame without 

 burning. The metal carries the heat away from it as fast as applied, becoming 

 hot itself. After a while it will reach a temperature, provided the flame is large 

 enough, at which the paper will burn. 



This same phenomenon can be more strikingly exhibited by making a vessel 

 of paper, filling it with water, and applying heat. No matter how hot the flame 



