50 THE ORIGIN OP CREATION, 



diminishing in quantity as itr boils, while the bottom' of the 

 boiler and the steam are both increasing in temperature. 



As there is- thus a space filled only with gases between the 

 bottom of the boiler and the water, the boiler must at that part 

 soon become red hot. We have already found that steam, in 

 passing through a red hot pipe, has the oxygen absorbed from it. 

 The same result follows here; the red hot metal "absorbs" 

 chemically all the oxygen gas derived from the hot steam, and 

 at the same time throws off its mineral or metallic (hydrogen) 

 gas, which takes the place of the oxygen until the Avhole becomes 

 in consequence only hydrogen. 



"We have thus in the boiler, the hydrogen at the bottom, the 

 water in the middlesuspended and the steam at the top. 

 But as in water there are eight parts of oxygen to one of 

 hydrogen, it follows that the steam at the top, being the same 

 in proportion as the water, is almost wholly composed of oxy- 

 gen gas. We have stated before that oxygen and hydrogen^ 

 when separate or alone, are incombustible, but when mixed in 

 certain proportions they form, or become, one of the most ex- 

 plosive compounds. It follows, then, that should the hydrogen 

 at the bottom, and the oxygen at the top, come into contact, 

 the explosion thafr would ensue will suffice to rend the strong- 

 est boiler ever made, and the greater the resistance offered, the 

 greater the explosion and destruction would be. The materials 

 being in the position indicated, suppose we open the valve, or 

 start the engine, the pressure is relieved on the top by allowing 

 the steam to escape, but what is the next result ? The water 

 immediately, by its " gravity," falls to the bottom, the hydrogen 

 gas is forced up, the gases intermingle, and, as the opening 

 is- not large enough- for the steam to escape in time, an ex- 



