( 44 ) 
Ba CO; + 2 Na Cl Ba Cl, + Naz COs 
which in our case, where a small quantity of Ba CO; could react 
with a very large excess of Na Cl, practically took place only from 
the left to the right. 
7. Being thus obliged to abandon this method, we have taken 
another course. 
A current of air free from carbon dioxide was first passed through 
a washbottle containing 300 ce. of distilled water and then through 
a little washbottle filled with baryta water; the current of air being 
thus again freed from carbon dioxide was passed through a wash- 
bottle containing 300 cc. of a 15 percent solution of NaCl and 
then finally through a small washbottle containing baryta water. 
If now a piece of black paper was put underneath the bottles 
containing the baryta it was plainly noticed, that, after 5 minutes 
the first bottle contained already more Ba CO; than the second one, 
which difference was maintained even after passing the gas for 
several hours, thus freeing the water and the solution completely 
from carbon dioxide. 
In this manner we had succeeded after all in demonstrating that 
the 15 percent solution of NaCl contained less dissolved carbon 
dioxide than the distilled water from which it had been prepared. 
On dissolving NaCl in water some of the CO, must, therefore, have 
been expelled. 
8. As regards experiment 3 we may state that STARKE has made 
another mistake. NaCl may be precipitated from a concentrated 
solution by addition of either H Cl or NaOH. The solution of the 
latter if used for this purpose should, however, be much more con- 
centrated than the HCl solution. There exists therefore, only a 
quantitative difference which may be explained by the difference in 
the degree of dissociation of equally concentrated solutions of H Cl 
and Na OH. 
From the foregoing we see how, in this subtile question, STARKE 
has wandered from the right path through not sufficiently criticising 
his own results, and has arrived at totally wrong conclusions. His 
theory being based on erroneous principles must, therefore, be entirely 
rejected. 
Amsterdam, Chem. Lab. University, May 1901. 
