THE BURNING OF INFLAMMABLE AIR 



delivering the gas. The density of the gas was determined 



in the same way as in the case of hydrogen, by finding the 



pressure produced in the three large 



globes by a known weight of the gas. 



In a typical experiment 23*0269 



grams of the gas produced a pressure 



f 753'97 mm - m a volume of 



43-3628 litres; density 0-535513; 



mean of 10 experiments 



0*5355 10 0*000010. From this 



density the proportion of hydrogen 



to oxygen was calculated, after 



making various corrections, to be 



2*00357. By exploding the gas in 



a eudiometer it was found that 



there was a slight excess of hydrogen, 



amounting to 0-000293 f trie total 



volume or 0*00088 of the volume of 



the oxygen. The combining volumes 



were therefore in the proportion 



hydrogen : oxygen = 2 '00269 : 1. 



A second method of determining 

 the composition of water was by 

 weighing the water produced by the 

 combination of known weights of 

 hydrogen and oxygen. The hydro- 

 gen (21 litres) was drawn from a 

 palladium bulb a (Fig. 30) provided 

 with a drying tube of phosphoric 

 anhydride b, and a tiny plug of 

 fusible metal c in place of a tap. The 

 oxygen (42 litres) was drawn from two large globes which 

 were weighed in the same way as in the density experiments. 



The combustion was carried out in a cylindrical glass 

 tube (Fig. 31) surrounded with cold water (Fig. 32) and 



K 2 



FIG. 31 MOKLEY'S COM- 

 BUSTION-TUBE. 



The gases were admitted 

 by jets aa after passing 

 through drying tubes bb ; 

 they were ignited by 

 sparking at ff. 



