Melt chocolate in the top of a double boiler and set aside to cool.
Combine sugar, water, corn syrup and salt in a heavy saucepan. Place over
low heat and stir only until mixture begins to a boil; cover pan and boil gently
for 5 minutes. Uncover and cook without stirring to 252 degrees F (hard ball
While syrup is cooking, in a large mixing bowl, beat egg whites until stiff
As soon as the syrup reaches hard ball stage pour it in a steady stream
into egg whites, beating constantly with an electric mixer at high speed. Continue
beating until the mixture begins to lose its gloss and it is stiff enough to
hold its shape when dropped.
Quickly blend in chocolate and vanilla.
Drop by teaspoonsful onto wax paper.
Cool completely, and store in a covered container.