Strychnine (Kuchila) is an alkaloid prepared from the seeds of Nux vomica tree. It is a colorless crystal with bitter taste (hence not ideal as homicidal poison). It is used to kill ‘pests’, from earthworms to dogs. There is no justification for its continued use or even manufacture, as it has no longer any place in medical treatment (used in …

Arsenic itself is not poisonous; it is the compounds of arsenic, particularly arsenous oxide or arsenic trioxide (sankhya or somalkhar) and various arsenites of Cu, Na and K that are toxic to the humans. Arsenic trioxide is a component of fruit sprays, weed-killers, dyeing agents, insecticides, rat poisons, etc. and also a medical preparation called Fowler’s solution (used in past …