What happens to Gaspard in Book 2 Chapter 15 & 16A Tale of Two Cities by Charles Dickens

In Chapter XV of Book the Second of A Tale of
Two Cities, the mender of roads climbs the stairs to the garret where once
Dr. Manette had been housed by Ernest DeFarge.  There he relates the story of Gaspard,
the father of the poor child that was run over by the Marquis d'Evremonde's carriage. 
Gaspard had grabbed hold of the chain beneath the carriage of the Marquis and traveled
with it to the chateau where later that night, he killed the
Marquis.

Now, the mender of roads tells DeFarge and the
others that Gaspard was captured;his arms tied to his sides, he was led by six soldiers
to the prison on a hill where he was locked in a cage yet with his arms bound.  Finally,
he was brought to the fountain where a gallows is fixed right above the fountain. There
he is hanged forty feet high--"and is left hanging, poisoning the water."  When he and
Madame DeFarge hear this story, Madame Defarge registers "The chateau and all the race"
in her knitting, and M. Defarge declares, "Extermination."