In any case, I have never seen him or heard of him since.
"If you have had patience to read as far as this, you will understand that I am not sure enough yet of my own discoveries to risk communicating them to any other person than yourself.

Favor me with any chemical suggestions which may strike you--and then, in case of accidents, destroy the cipher.

For the present farewell." _Note to Doctor Fontaine's Letter_ "Alexander's Wine" refers to the infamous Roderic Borgia, historically celebrated as Pope Alexander the Sixth.

He was accidentally, and most deservedly, killed by drinking one of the Borgia poisons, in a bowl of wine which he had prepared for another person.
The formula for "The Looking-Glass Drops" is supposed to have been found hidden on removing the wooden lining at the back of a looking-glass, which had been used by Lucrezia Borgia.

Hence the name.
III The third and last letter which I present is written by me, and was addressed to Mrs.Wagner during her stay at Frankfort:-- "I exaggerate nothing, my dear aunt, when I say that I write in great distress.