This section is from the book "The Steward's Handbook And Guide To Party Catering", by Jessup Whitehead. Also available from Amazon: Larousse Gastronomique.
Is of several kinds.
Fine powdered sugar wetted with water, and flavored, and spread over the surface of the cake. It is of a pearly, semi-transparent appearance, and does not break when the cake is cut. Is also made with fruit-juices or syrup instead of water, or with wine, or colored with any confectionery coloring.
Creamed sugar, such as chocolate-cream drops, etc., are made of, is partially dissolved and poured and spread over cakes while warm, and considered the best kind of icing. It contains no white of eggs, but the sugar is boiled to the degree of soft ball, then worked with a paddle on a slab till perfectly white.
TUBES FOR CAKE ORNAMENTING.
Powdered sugar wetted with white of egg and beaten with a paddle about 15 minutes, or till firm and white. A little acid of any harmless kind assists in the making. When firm enough to pipe ornaments on the cake, part of it is thinned down with more white of egg to spread over the surface of the cake smooth and glossy; the ornamenting is put on when the coating is partly dry.
Grated chocolate beaten into boiling sugar at the stage of the "feather" or soft ball, a little lard or fat of some kind added to make it glossy.
Made with yolks and sugar; or, white icing colored.