NARRATIVE OF THE CRUISE. 



17 



until the flask is overflowing. The opening c in the tube is then brought just below the 

 lower surface of the cork, which is pressed tightly into the neck of the flask. A certain 

 amount of water is displaced by the cork, rises into the bulb, and the tube is carefully 



Fig. 8.— Apparatus for collecting the Atmospheric Gases from Sea-Water. 



drawn upwards till the opening is well within the cork and therefore closed. A certain 

 suction or diminution of pressure is produced, causing the immediate appearance of 

 air-bells in the water. The receiver b is now attached, and the water in the bulb brought 

 (narr. chall. exp. — vol. i. — 1884.) 3 



