>5 

 HYDROGEN. 7 



owing to its power of absorbing gaseous and other 

 substances, itself being full of pores. 



Both the flarae that we see in wood, and the bright 

 glow of coal fires, are owing to the burning of carbon ; 

 the flames of candles, of oil lamps, of ordinary coal 



f;as, are all colored by the combustion of this substance- 

 t will soon be seen that it constitutes a very large 

 proportion in the organic part of all vegetables and 

 trees. 



Hydrogen, as I have said, is a gas, or kind of air. 

 It is transparent, tasteless, colorless and inodorow. 

 As we can not smell, taste or see it, we can only judWB 

 of its properties by its action with other bodies. For 

 this purpose it is obtained by putting pieces of zinc 

 or iron tilings into water, and then adding sulphuric 

 acid, that is, the common oil of vitriol. About a third 

 as much acid as water should be use<i. The mixture 

 will soon grow warm, and hydrogen gas will at once 

 commence ri^ng to the surface in little bubbles. 



a. V ' -s be laid upon the top of the tumbler 

 C-ontai mixture, so as to prevent the too rapid 



escape of tlu; gas, the tumbler will in a few moments 

 become so filleii that the gas will burn when a flame 

 is brought into contact with it 



ft. By far the most ^^ , 



■atisfactorv method is 

 !.. ' ■' '• ■ .Ta- 

 t, 1 in 



fig. 1. In tl)«- lK)ttIc 

 are placctl the sul- 

 phuric acid, zinc, and 



\V:iti'r X^i.. iTimifli of 



f' .-.! 



ti;.;niiv iiv :i (oik, i ' vhich pa«sses onc end of the 



tube a (this may ' •>« or tin); the other end 



passes under water m tin-, • "■ its roiintc being 



