1905-6.] Dr W. W. Taylor on The Theory of Ionization. 325 
Two Lecture Experiments in illustration of the Theory 
of Ionization. By Dr W. W. Taylor. Communicated 
by Professor Crum Brown. 
(MS. received July 2, 1906. Read July 2, 1906.) 
The two experiments, which, so far as I am aware, have not 
hitherto been described, illustrate two of the conclusions drawn 
from the theory of ionization. The first is that the degree of 
ionization of a solution of an acid is diminished by addition of a 
salt of the acid. The experiment differs from many of those 
employed for the purpose in that it demonstrates the increase in 
concentration of the un-ionized acid, and not the diminution of 
activity as an acid, i.e. decrease in concentration of H*. A solution of 
egg-albumin is added to a solution of nitric acid which is so dilute 
that no coagulation of albumin occurs; a saturated solution of 
potassium nitrate is then added to the mixed solution, and coagula- 
tion immediately takes place. The potassium nitrate solution causes 
no coagulation when the nitric acid is not present. 
That un-ionized nitric acid causes the coagulation is shown by 
the fact that H*, K", N 0 3 ', and un-ionized potassium nitrate do not 
do so under the same conditions. 
The second experiment illustrates the proposition that, on 
addition of a weak acid to a solution of a salt of a strong acid, 
some of the strong acid is displaced by the weak acid. Saturated 
solution of potassium nitrate, added to an albumin solution, 
causes no coagulation ; a solution of acetic acid likewise causes 
no coagulation when added to the albumin solution. When the 
two are added to the albumin, coagulation takes place immediately. 
That in this case, also, the precipitation is due to the formation 
of un-ionized nitric acid is shown by the facts that H", K’, N0 3 ', 
C 2 H 3 0 2 ', and un-ionized potassium nitrate do not cause it. 
A separate experiment with potassium acetate, the only other sub- 
stance formed in the reaction, proves that the precipitation is not 
