It is advisable when making provings to begin with a single dose, but in the great majority of cases this will cause no effect. If the single dose fails we may try to create a susceptibility by repeating the dose until some effect is produced, but the medicine must be stopped at once on the appearance of symptoms and not repeated until absolutely all symptoms have ceased.
Many provings, especially some of Thuja, are almost valueless owing to this repetition of the drug after symptoms appeared. The finest symptoms, as a rule, are those that develop late months after the drug has been discontinued. No heed must be paid as to whether the symptoms in a proving are primary or secondary, for as long as the drug can produce them it can cure them. In certain provers what are commonly regarded as secondary symptoms appear as the primary action of the drug.
In a proving, if symptoms appear which have been experienced long before, this re-appearance only proves that in virtue of his own constitution this prover has a special tendency to admit their manifestation.- (Organon, par. 138).