Manchesler Memoirs, Vol. Ixi. (1917), No. \i. 3 



iiicnt in so far as the action of nascent hydrogen is concerned, 

 they chffer as to the action of free hydrogen on sulphuric acid 

 particularly in two ways : (c?) as to temperature, ih) as to the 

 effect of impurities in the gas. 



It seemed to me worth while to endeavour to dc\'ise an 

 experiment that would settle the ponits at issue. 



The bulb A of the non-tubulated retort {see sketcli) con- 

 tains strong sulphuric acid, and the rest is filled with pure 

 hydrogen, tlic point dips under water in the test glass B, and 

 the whole is left at the ordinary temperature for several days. 

 If sulphur dioxide is produced, it will be dissolved by the 

 water, which ought to rise slowly in the neck of the retort. 

 This is exactly what occurs. The reaction is slow but steady. 

 Even a slight impurity in the hydrogen would not account 

 for the gradual diminution in the volume of the gas, which 

 can only be accounted for by the supposition that hydrogen 

 acts on the sulphuric acid at the ordinary temperature in the 

 way suggested by the equation — 



The height of the liquid in the neck of the retort {see 

 sketch) represents approximately the result of an experiment 

 continued for twenty days. 



