Mercuric chloride is highly toxic both directly and as a cumulative toxin. This toxicity is due not only due to the content of mercury but also due to the corrosive properties of this compound, which can cause significant internal damage, including stomach, mouth and throat ulcers, and corrosive bowel damage.
Used in photography, disinfectants, wood preservatives, fungicides. Mercury chloride (HgCl2) is a highly toxic compound that volatizes slightly at ordinary temperature and appreciably at 100 degrees C. It is corrosive to mucous membranes and used as a topical antiseptic and disinfectant.
Probable oral lethal dose is 5-50 mg/kg; between 7 drops and 1 teaspoonful for a 150 lb. person.