Key to Wisdom
The Key to Wisdom by Artephous is in the collection of Joseph Curwen. This is probably Artephius, a mystic who lived in the 12th century and wrote 'The Art of Prolonging Life,' which he was said to have written when he was 1025 years old.
[The Case of Charles Dexter Ward - H.P.L.]
See also: Artephous
Artephius's Secret Book on creating the philosopher's Stone and other works on alchemy can be found in the Miskatonic Library.