of Alcohol upon the Metal Palladium. 



37 



laboratory*; but he was unable to obtain satisfactory results 

 so far as the main question is concerned. 



The apparatus shown in the figure serves as a simple and 

 effective means of exhibiting the absorption of hydrogen by 

 palladium, a is a tall glass cylinder filled with water ; b is a 



divided tube of at least 100 cubic centims. capacity ; c is a very 

 narrow gas-delivery tube, one end of which passes under the 

 open end of the divided tube ; d is a tube for the palladium, 

 bent so that it can be placed in a vessel of boiling water ; e is 

 a chloride-of-calcium tube for drying the hydrogen ; / a glass 

 stopcock leading to a gas-holder. 



After a few grams of palladium sponge have been placed in 

 the tube d, whilst the one end of the tube remains open a cur- 

 rent of hydrogen gas is passed for some time over the metal 

 placed in the boiling water. In the mean time the tube b is 

 filled with water, and the cylinder as well as the tube c. After 

 the lapse of about half an hour the tube d is taken out of the 

 hot water and allowed to cool, the current of gas still passing 

 through. Then the stopcock/ is closed, the drawn-out end of 

 the tube d connected with the gas-delivery tube c and the 

 screw-tap loosed. 



The palladium is now heated ; and the occluded gas is quickly 

 set free and passes into the graduated tube b. As the metal 

 cools, the gas is again absorbed ; and at last all the hydrogen 

 disappears and the tube b becomes, as before, full of water. 

 An apparatus of this kind, fitted with glass stopcocks, may 

 therefore serve for exhibiting the experiment any wished-for 



* Th. Wood, 'The Action of Palladium on Carhon:' Gottingen, 1859. 



