vii THE BURNING OF INFLAMMABLE AIR 133 



The mean of twelve experiments in which 400 grams of 

 water were produced gave the ratios 



oxygen to hydrogen = 7 '%% 

 water to hydrogen = 8*9392 



From the ratio 15*9002 of the densities and 2*00269 f 

 the conjoining volumes, the two constituents are in the 

 ratio 



oxygen : hydrogen = 7*9395 : 1. 



The high order of accuracy reached in these modern 

 measurements on the composition of water is shown by the 

 following comparison of the values for o C. and 760 mm. 

 pressure. 



Ratio of densities Rayleigh 15*882 



,, (reduced to oC. ) 15*900 

 Morley ... ... 15*9002 



Ratio of volumes ... ... Scott ... ... ... 2*00245 



,, (reduced to oC.) 2*00285 



Morley 2*00269 



Ratio of weights Rayleigh & Scott ... 7*931 



Morley (a) 7 -9396 



(from oxygen : hydrogen) 



Morley (b) 7 -9392 



(from water : hydrogen) 

 Morley (c) _ 7*9395 

 (from combining volumes) 



SUMMARY AND SUPPLEMENT. 

 A. Water an Oxide. 



Cavendish, in 1781 (" Experiments^ Air," Part I, published 

 in 1784), showed that pure water, without taste or smell, was 

 produced by exploding or burning a mixture of inflammable 

 air with 2| times its volume of common air. Water was also 

 formed when that gas was exploded with \ volume of oxygen, 

 but in this case the product was slightly acid. 



Lavoisier, in 1783, prepared half an ounce of pure water by 

 burning oxygen and inflammable air. He also proved the 

 presence of oxygen in water by passing steam through a red- 

 hot iron gun-barrel, when inflammable air and magnetic oxide 

 of iron were produced. These experiments showed that water 



