Ammonium Carbonicum
Vithoulkas (Polderman, 1989, page 136) calls Ammonium carbonicum a 'sour prune', indifferent, unyielding, obstinate, irritable, coarse, insulting, rude, surly, whimsical, refuses to answer questions, timid, avoids crowds. Quite a list, but without much structure. It is not surprising that Vithoulkas commented: 'Personally, I wouldn’t prescribe this remedy on a purely mental picture, because we don’t know yet what is behind it all in Am-c'.