Stimulants and narcotics never act so quickly upon persons accustomed to use spirits freely as upon those who live abstemiously.
681. Climate
The action of medicines is modified by climate and seasons. In summer, certain medicines act more powerfully than in winter, and the same person cannot bear the dose in July that he could in December.
682. General Health
Persons whose general health is good bear stronger doses than the debilitated and those who have suffered for a long time.
683. Idiosyncrasy
By this is meant a peculiar temperament or disposition not common to people generally. For example, some persons cannot take calomel in the smallest dose without being salivated, or rhubarb without having convulsions; others cannot take squills, opium, senna, &c.; and this peculiarity is called the patient's idiosyncrasy, therefore it is wrong to