Aurina,
Thank you for your extra research.
Yes, I posted those FAG memorials. On a visit to NYC in 2009, I checked NYPL death indexes, Municipal Archives death indexes/records, NYPL newspapers, cemeteries, etc. So the info at FAG is verified. There was no record of Adolf after the two 1900 censuses. Obituaries for other family members offered no info about survivors; nothing in the Woodlawn cemetery records. Have accounted for burial locations/death records for all other family members so he's not with them.
Of course, have exhausted Ancestry and Family Search and other online sources with no luck.
Several years ago, I spoke with a town historian in Essex who essentially said most patients at Adirondack Cottage were cured, in which event, Adolf would have likely returned to his family, Yet I have the 1905 census for them and he's not there. That's why I suspect Adolf may not have survived his stay in the Sanitarium (sometimes referred to as the Trudeau Sanitarium).The sanitarium no longer exists nor do its records.
As I said, I don't know how the NYS death indexes are arranged - by year, surname, county, or ? - but, if 1900-1905 could be checked for Essex County, I would appreciate it.