May we assume Mr. Ruggles has chronic malaria?
This sounds like Mr. Ruggles is dotty (”peculiar temperament”), and then they gave him opium.
I never realized that Mr. Ruggles's temperament was peculiar. He seems to function pretty well, being tasked by Trinity Church with presenting their cases to both the state legislature and bodies of bishops. I don't know about malaria. George called the malady a severe cold in his first mention of the illness on the 17th. Maybe quinine was considered a treatment for other things. If Mr. R. caught cold on the train in winter maybe it is something we would treat with antibiotics today, like strep. I would want some opium if I had strep throat and had to let it run its course.
I took a peek into the future and there is only one further reference to Mr. R's illness - a concerned friend asks after him - so I guess he will recover his health shortly and return home.