List of top Forensic Medicine Questions on Toxicology - Cyanide (Hydrocyanic Acid) Poisoning

A case of poisoning was brought to the casualty, a gastric lavage was done, and the lavage turned black when it was heated after being treated with silver nitrate. The poisoning is most likely to have been due to which of the following?

Two farmers were brought dead, autopsy done revealed viscera that had the smell of bitter almonds. The most likely poisoning is due to that by?