Mix first 5 ingredients together and cook slowly in heavy 4-quart boiler (or pot large enough to keep from boiling over) to firm ball stage (238° F on candy thermometer).
Add salt and vanilla extract. Pour into buttered 12 x 9-inch pan and let cool. This will take several hours.
When cool, cut into squares and wrap in wax paper. Will keep for several weeks.
Servings: 9 dozen