Sentence:  No one, who uſes his Senses, can possibly doubt, but there is "ſomewhat of a <WSD>vitriolic</WSD> Nature" found in "Mineral Waters": for not only the Taſte, but the Sight confirms it, by their turning inky with "Galls", &c. 
Meaning of the word marked with <WSD> tags:  Of or pertaining to vitriol; derived from or resembling vitriol; vitriolous.