( 186 ) 
above, and that in a following paper a communication will be made 
as to the experimental confirmation. 
At the same time the v,x- and p^-figures will be considered, which 
allow a closer investigation of the said remarkable phenomena. 
Amsterdam, June 1909. Inorg. Chem. Lab. University. 
Chemistry. — 11 On the compounds of ammonia and water." By 
Prof. A. Smits and S. Postma. (Communicated by Prof. A. F. 
Holleman). 
(First Communication). 
(Communicated in the meeting of June 26, 1909.) 
Often it has been asked what happens when ammonia and water 
come together, but nobody has succeeded as yet in giving an entirely 
satisfactory answer. 
That we are dealing here with a chemical transformation besides 
the physical process, is shown by the deviations from Henry’s law 
as well as by the great heat of mixing; but the nature of this chemical 
transformation is as yet unknown. 
If we consider what are the most important facts which we have 
learned in respect to the solutions of NH 8 in water, these are the 
following ones: 
On dissolution of NH, in water the OH'-ion concentration is increased, 
so that NH, dissolved in water behaves as a comparatively weak base. 
It further appeared that the solution contains the same NH 4 -ions 
as are split off from ammonium salts, as the electrolytic dissociation 
in the aqueous NH,-solution can be reduced not only by increase of 
the OH'-ion concentration, but also by increase of the NH 4 -ion con¬ 
centration. 
The fact that free ammonia is present in an aqueous solution of 
ammonia was shown by Hantzsch and Sebaldt j ) ; they shook such a 
solution with solvents for NH, such as chloroform from which it 
appeared that the distribution of NH, between water and chloroform 
depends on the temperature; at higher temperature more NH, passes 
into the chloroform layer. 
From this has been drawn the conclusion that on dissolving NH, 
in water we are dealing with' a compound whose concentration 
increases with a decrease in temperature. 
The behaviour of the substituted organic ammonia derivatives 85 
!) Zeitschr. f. phys. Chem. 30, 258 (1899). 
