Final answer:
Helen slips a drug called 'heart's-ease' into the mixing-bowl, which prevents anyone who drinks it deeply from feeling pain or shedding tears.
Step-by-step explanation:
Helen takes the action of slipping a drug called 'heart's-ease' into the mixing-bowl. The effect of this drug is that anyone who drinks it deeply will be unable to cry or feel any pain, even in the face of tragic events like the death of a loved one or the loss of a family member.