In attempting to analyze this "abstract of symptoms," to see if the internal evidence tends to show that the recorded effects are genuine results of the drug, it is well to remember that these provings--for we infer that three observers participated therein--were made in the light of the empirical history of _Pothos foet._ The said history was on record before the date of these provings, and it cannot have escaped Hering's eye; he was too wide a reader for that. He was, beyond doubt, aware of the pathogenetic effects observed by Bigelow--_headache_, _vertigo_, _temporary blindness_, _vomiting_, _even from small quantities_. Having, then, this clue to its physiological action, these symptoms should reappear in his proving _if his imagination furnished his symptoms_. As only a mild headache is noted in the _Correspondenzblatt_, it is evident that these provers did not _work from a pattern_. It is also evident that the _usus in morbis_ did not suggest the Allentown symptomatology, for the anti-asthmatic virtue of _Pothos foet._ is one feature on which the greatest stress had been laid, and yet the only _pathogenetic_ suggestion of its applicability in asthma is: "_Sudden feeling of anxiety with difficult_ (or oppressed) respiration and sweat, followed by stool and the _subsidence of these and other pains_." Who ever heard of an asthma relieved by stool? Who could have _invented_ such an odd modality? As it stands it is an _unicum_, and by every rule of criticism this single symptom-group gives the stamp of verity to the Allentown "abstract of symptoms." But there is other and singularly convincing evidence of the genuineness of this abstract. As the reader is aware, Thacher had emphasized the efficiency of _Pothos foet._ as an anti-spasmodic in hysteria, although the "key-note" that indicates it in hysteria had wholly escaped his discernment. Now this very "key-note" appears in the Allentown pathogenesis, but so unobtrusively as to show most conclusively that the prover who furnished it did not recognize its singular import and value. Such testimony is absolutely unimpugnable by honest and intelligent criticism. It is also apparent that some of the less pronounced of its empirical virtues are reflected in the proving. For instance, Thacher found it efficacious in "erratick pains of a spasmodick nature." Is not this "erratic" feature reproduced in such conditions as: "Headache, of brief duration, in single spots, now here, now there?" "Pressure in both temples alternately, harder on one side than on the other?" "Bellyache, here and there, in single spots?" Brevity of duration and recurrence "in single spots, now here, now there," are phenomena at once _spasmodic_ and _erratic_. It must be admitted that the trend of its pathogenetic action and the lines of its therapeutical application are parallel, and, therefore, that the latter are confirmatory of the former.