436 J. P. Cooke— New Mode of Manipulating Hydric Sulphide. 



pressing the foot on a pedal shown at the base of the apparatus 

 the siphon — confined in a cage — is raised, so that its mouth i 

 forced tightly against one opening of a valve of peculiar cor 

 1 by a block-ti 



tube to a fountain ; while at the same time the handle of the 

 siphon is pressed back. On now pushing the upper lever 

 shown in the cut to the right, the valve of the fountain having 

 been previously opened, a connection is made between the 

 fountain and the siphon ; when the charged water rushes into 

 the latter, condensing the air to a fraction of its original 

 volume. If next the same lever is pushed momentarily to the 

 left, the first connection is closed ; while a vent is opened, 

 through which the condensed air rushes out into the atmo- 

 sphere before the gas in solution has time to escape, and then 

 on pushing back the handle a further portion of liquid enters, 

 nearly filling the interior of the bottle. Lastly, on raising the 

 foot, the valve of the siphon shuts at the same time that the 



