Scrape fine an ounce (one of the small squares) of Baker's or any other plain
chocolate. Add two table-spoonfuls of sugar, and put in a small saucepan with a table-spoonful of hot water. Stir over a hot fire for a minute or two, until it is perfectly smooth and glossy, and then stir it all into a quart of boiling milk, or half milk and half water. Mix thoroughly, and serve at once. If the
chocolate is wanted richer, take twice as much
chocolate, sugar, and water. Made in this way,
chocolate is perfectly smooth, and free of oily particles. If it is allowed to boil after the
chocolate is added to the milk, it becomes oily and loses its fine flavor.
Source:
Miss Parloa's New Cook Book