AdeNey and Becker — Solution of Nitrogen and Oxygen. 619 



The manipulation involved in an experiment was as follows : — After the 

 whole apparatus had been carefully cleaned, the manometer was filled with 

 water and the tube filled with mercury by connecting on a temporary reservoir 

 at B\ at the same time the gas reservoir Cwas filled with mercury by raising 

 E. The water-level in B was also raised to the hollow stopper, which was 

 then turned so as to close all the side tubes. The tube was then connected 

 to the boiling apparatus just described, by a capillary tube joined to stop- 

 cock F. The air was displaced from this connexion by forcing a little 

 mercury over from the temporary reservoir. The water was then boiled 

 until all the air was extracted, when the water was displaced over into the 

 experimental tube, by lowering the reservoir of mercury attached to it, and 

 raising that attached to the laboratory flask. 



When the tube was quite full it was disconnected from the laboratory 

 flask, and water from the thermostat was circulated through the jacket until 

 the required temperature was attained. When a steady state was reached 

 the stopcock F was connected to the reservoir of gas in use, and the stopcock 

 B to a standard burette, and the correct volume of bubble drawn in. The 

 gas reservoir C was then filled with the gas by turning the stopper so as to 

 connect it with the bubble, and lowering the reservoir E; the manometer 

 space was likewise filled by again turning the stopper and lowering the 

 manometer tube 67. The tap at F was then disconnected from the gas reservoir 

 and opened and shut several times so as to bring the manometer to zero and 

 the pressure in the bubble to that of the atmosphere. (The pressure in the 

 bubble before this operation was always slightly above atmospheric, so that no 

 air could enter.) 



The tube was then ready for the observations which were made as usual 

 after each double inversion. During the inversion the stopper was turned so 

 as to shut all side tubes, and it was so arranged that after inversion the 

 bubble could be connected to the manometer alone, to read the pressure, and 

 then to the manometer and gas reservoir simultaneously, to allow of the 

 pressure being re-adjusted to atmospheric, by manipulating the mercury 

 reservoir E until the manometer went back to zero. 



By means of this apparatus the difficulty about the temperature and 

 vapour-pressure of the replenishing gas was overcome, because the gas was 

 contained in the reservoir C at the same temperature as that of the bubble, 

 and there was sufficient moisture in the reservoir to keep the gas saturated 

 with aqueous vapour at that temperature. 



When the observations were completed, the lower tap B was connected 



to the gas pipette described in Part I of this communication, by means of a 



piece of rubber tubing filled with mercury, and the water in the tube was run 



5e2 



