Know the Remedy
Once you've identified two, maybe three, strong candidates as a remedy from Kent's or another repertory, you're ready to study those candidates in detail, to learn the their nuances and how their profiles compare to that of the illness or disease. To do that you'll need to obtain a reference known as a "Materia Medica" for homeopathy. The Materia Medica is a compendium of homeopathic remedies, describing hundreds, if not thousands, of remedies — derived from plant, mineral, and even animal substances — based on all their observed characteristic and other symptoms, along with their keynotes (central themes or disturbances), as has been demonstrated in tests or "provings" of these remedies' effects on healthy individuals and in clinical practice. Examples of such compendiums include Materia Medica of Homeopathic Medicines by Dr. S.R. Phatak and Concordant Reference by Frans Vermeulen.
Remedy Profile
The Materia Medica profiles each remedy in two significant ways, through symptom listings and keynotes. Let's take a closer look at each of these.
Symptom listings
The Materia Medica lists all the observed symptoms of various substances organized, in some accord with the Repertory, under anatomical regions, functions, and general conditions or enjoyments of the body (for example, Mind, Head, Eyes, Vision, Ears, Nose, Stomach, Food & Drink, Abdomen, Rectum, Chest Fever, Chill, Upper, Lower, Sleep, Dreams, Skin, etc.). We'll cover an example later in the section below, Example: Arsenicum and Nux Vomica.
Keynotes
Another major feature of the Materia Medica are the keynotes, or the central themes or disturbances that run throughout the majority of cases and which have been observed in clinical practice. For example, the remedy Cantharis expresses a theme of burning throughout its symptom profile. Therefore, it has such keynotes as burning pain, burning during or around urination, and relief and healing from a severe burn (Desktop Guide to Keynotes and Confirmatory Symptoms, by Roger Morrison, M.D.). For an example of how keynotes are used in treatment, see the section below, Example: Arsenicum and Nux Vomica.