226 LORD RAYLEIGH AND PROFESSOR W. RAMSAY ON ARGON, 
remarkable manner, but to make this method effective, some means of circulating the 
water would have to be introduced. 
The extraction of the gases by heat proved to be more manageable. Although a 
large quantity of water has to be brought to or near 100° C., a prolonged boiling is 
not necessary, as it is not a question of collecting the whole of the gas contained in 
the water. The apparatus employed, which worked very well after a little experience, 
will be understood from the accompanying figure. The boiler A was constructed 
Fig. 8. 




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from an old oil-can, and was heated by an ordinary ring Bunsen burner. For the 
supply and removal of water, two co-axial tubes of thin brass, and more than four feet 
in length, were applied upon the regenerative principle. The outgoing water flowed 
in the inner tube BC, continued from C to D by a prolongation of composition 
tubing. The inflowing water from a rain-water cistern was delivered into a glass 
tube at E, and passed through a brass connecting tube FG into the narrow annular 
space between the two principal tubes GH. The neck of the can was fitted with an 
india-rubber cork and delivery-tube, by means of which the gases were collected in 
