But since you've selected that particular source, which does nothing to contradict anything I've said, I'll point out that the same source exposes Watie's fabrication about the invention of heroin. "Like aspirin, heroin had already been discovered in 1874 by English chemist C.R.A. Wright,"
Bravo Sierra! Aspirin as we know it is acetylsalicylic acid. An application for a German patent was rejected, because in fact acetylsalicylic acid was not a new substance, having been first synthesized in 1853 by French chemist Charles Gerhardt, in impure form, and later in crystalline form by German chemist Carl J. Kraut.
Gerhart discovered how to "buffer" aspirin in 1853, but the purified unbuffered aspirin (salicylic acid) was produced in 1838 by Italian chemist Raffaele Piria.
Grant could have easily ingested unbuffered 'aspirin'.