Put one quart of milk in a double boiler. When hot add one teaspoon of corn
starch wet with a little cold water, add salt and butter and cook long enough to
cook the starch. Take one can of Campbell's tomato soup and put in another dish.
When hot, add one-fourth teaspoon of soda; after it foams stir into the milk and
serve. . Mrs. Frederick J. Seaver.
Source: The Malone Cookbook 1917