46 



K. IKEDA. 



is not constant as it should be, but grows gradually larger. This 

 may be owing to the heating effect of oxidation, or to some other 

 cause. For one thing the manometer being hastily extemporized did 

 not allow of any exact reading. On the whole, the experiment was a 

 hasty and rough one, and the result must not be regarded as final. 

 Still the general agreement with the law of mass action is apparent. 



With a strong solution of mercuric iodide in potassium iodide 

 solution, or some other heaving liquid properly coloured, as the 

 manometric liquid, this arrangement may be employed in a lecture 

 experiment to illustrate the simple principle of chemical kinetics. 



The second arrangement. 



A burette B of 100 c.c. capacity and 18 m.m. 

 internal diameter was connected with a water reservoir 

 C and surrounded with water as shown in Fig. 3. The 

 phosphorus cylinder was introduced into the upper part 

 of the burette ; and after adjusting the level of water in 

 B and C, the volume of air in the former was accurately 

 observed which gave, with proper correction, tlie initial 

 volume ^0=93.5 c.c. The observation was repeated 

 every five minutes, the pressure in 1> being always kept 

 equal to that of the external atomos]:>here, so that the 

 diminution of the volume x here denoted the amount 

 of oxygen absorbed. The result is shown in the follow- 

 inof table. 



Fig. 3. 



