Sentence:  [A] small dose of the <WSD>mercurial</WSD> may cause excessive salivation; and, if this discharge be attended by much soreness of throat, it is most difficult to determine whether the salivation is actually the result of the <WSD>mercurial</WSD>, or merely symptomatic of the sore throat and cold. If it proceed from the <WSD>mercurial</WSD>, there will generally be some tenderness of the gums, a soft and flabby state of the sides of the tongue, and it will generally be more obstinate. 
Meaning of the word marked with <WSD> tags:  A preparation of mercury, especially as a treatment for syphilis. (from 17th c.)