Silver is a non-toxic element. However, most of its salts are poisonous due to the presence of its anions. These compounds are absorbed by the body and remain in the blood stream until they are deposited in the mucous membranes, forming a greyish film. However, there are some silver compounds, like the nitrate, with an antiseptic effect. Solutions of silver nitrate are used in treating irritations of mucous membranes in the mouth and throat. Some proteins that contain silver are powerful anti-irritating agents of the membranes of the eyes, heard, nose and throat.