Sentence:  The Observations of the Effects of these Waters on Persons who use them in Drinking, Bathing, Pumping, Washing, <WSD>Embrocation</WSD>, &c. are reserv'd for the Physicians, whose Duty it is to know the Particular Constitutions of those Persons, and the State of their Health Declining or Improving. 
Meaning of the word marked with <WSD> tags:  The act of moistening and rubbing a diseased part with spirit, oil, etc.