Hahnemann discovered the idea of Psora when he found his remedies in many instances had failed to cure diseases completely. If his Law of Homoeopathy was true, the indicated remedies should have removed the disease in toto. The fact that they did not do so only meant that they did not cover the complete totality of symptoms, but only one facet or phase of a much bigger disease.
Each one of these so-called specifics is only a starting point from which to expand. For instance take the first one, herpes zoster. Of it J. Compton Burnett says, “Variolinum wipes out herpes zoster, pain and all.” Mezereum for herpes zoster has, “Severe neuralgic pains; itching after scratching turns to burning, worse from touch and in bed; chilly; sensitive to cold air; vesicles form a brownish scar”.
One does not have to be in practice long to come in contact with a child to which one would like to apply Quercus (the species does not matter) in quite material dosage to the north elevation of the child while it is facing south at the level midway between the coronal suture and the os calcis.
Hahnemann has, in his writing, given full credit to Hippocrates by quoting him, and every other medical writer since his day where there was to be found any conscious or unconscious acceptance or use of the principle of similars, only taking to himself the credit of seeing clearly for the first time and enunciating fully and completely what had been so dimly perceived before him as to result in practically nothing.
It is certainly closely related to all three of the chronic miasms, an anti-syphilitic, anti-sycotic, anti-psoric. It deserves careful study and quick recognition when indicated, for it will bring relief and peace to many a sufferer. This may be said to be true of the acid group of remedies in general, but Nitric Acid is much better known than most other acids, having had thorough proving and good clinical testing.