Organon aphorism §157

But though it is certain that a homeopathically selected remedy does, by reason of its appropriateness and the minuteness of the dose, gently remove and annihilate the acute disease analogous to it, without manifesting its other unhomeopathic symptoms, that is to say, without the production of new, serious disturbances, yet it usually, immediately after ingestion—for the first hour, or for a few hours—causes a kind of slight aggravation when the dose has not been sufficiently small and (where the dose has been somewhat too large, however, for a considerable number of hours), which has so much resemblance to the original disease that it seems to the patient to be an aggravation of his own disease. But it is, in reality, nothing more than an extremely similar MEDICINAL DISEASE, somewhat exceeding in strength the original affection.

Organon aphorism §158

This slight HOMEOPATHIC AGGRAVATION during the first hours—a very good prognostic that the acute disease will most probably yield to the first dose—is quite as it ought to be, as the medicinal disease must naturally be somewhat stronger than the malady to be cured if it is to overpower and extinguish the latter, just as a natural disease can remove and annihilate another one similar to it only when it is stronger than the latter (§ 43-48).

Organon aphorism §159

The smaller the dose of the homeopathic remedy is in the treatment of acute diseases so much the slighter and shorter is this apparent increase of the disease during the first hours.