CHEMISTRY: E. C. FRANKLIN 
581 
ordinarily recognized as acids at all. The acid properties of acetamide, 
urea and other very weak ammono acids, however, show themselves 
distinctly when in solution in liquid ammonia as has been shown by 
the writer and his students in earlier papers. 
The fact that acids too weak to be recognized as such in aqueous 
solution are still capable of showing acid properties when in solution 
in liquid ammonia is undoubtedly due to the lower solvolytic^ action 
of ammonia as compared with water which in turn results from the very 
slight autoionization of the former solvent. To what extent liquid 
ammonia is dissociated has not been accurately determined. Since, 
however, it is a comparatively easy matter to obtain liquid ammonia 
with a specific conductance less than one-eighth that of water^ it must 
be considerably less ionized than is the latter solvent. 
It happens therefore that salts of the weaker ammono acids, which, 
because of the strong hydrolytic action of water are incapable of ex- 
stence in the presence of this solvent, have been easily prepared from 
liquid ammonia solutions. 
CH = CH\ /^^\ 
Pyrrol, | NH, indol, C6H4 CH and carbazol, 
ch = ch/ \nh/ 
C6H4\- yCoHiy are obviously derivatives of ammonia in which 
ammonia hydrogen is replaced by distinctly negative groups. They 
are therefore to be classed among the ammono acids and as such should 
react, in liquid ammonia solution, with the more electro positive metals 
and with their amides, the ammono bases, to form salts. 
Experiments will be described in a paper to be printed in the Journal 
of Physical Chemistry showing that pyrrol, indol and carbazol react in 
liquid ammonia solution with metallic potassium, sodium, calcium and 
magnesium and with the amides of potassium, sodium, calcium and 
silver to form the following well defined salts : 
Sodium pyrrol, C4H4NNa and C4H4NNa.NH3. 
Calcium pyrrol, (C4H4N)2Ca and (C4H4N)2Ca.4NH3. 
Magnesium pyrrol, (C4H4N)2Mg. 2NH3. 
Silver pyrrol, C4H4NAg.NH3. 
Sodium indol, CsHgNNa . XNH3. 
Potassium indol, C8H6NK.XNH3. 
Calcium indol, (C8HGN)2Ca.4NH3. 
Magnesium indol, (C8H6N)2Mg.4NH3. 
