Put egg yolks, lemon juice, and mustard in top of a double boiler or in a round-bottomed medium bowl and set over simmering water.
Melt wax and chocolate chips together in a double boiler.
Place it in the top of a double boiler over simmering water.
Melt first three ingredients in top of double boiler.
Combine the oil of rosemary, almond oil, glycerin and lanolin in the top pan of a double boiler.
Mix gelatin, half the sugar and the salt in the top of a double boiler.
Combine the butter, sugar, and cocoa powder in a double boiler and heat until melted.
Place the egg mixture over a double boiler and begin to heat.
In a medium stainless steel bowl, or top of a double boiler, combine the remaining ingredients.
Reheat them in a double boiler, adding a little chicken broth, water or cream to thin them if necessary.
British Dictionary definitions for double boiler
(US & Canadian) a cooking utensil consisting of two saucepans, one fitting inside the other. The bottom saucepan contains water that, while boiling, gently heats food in the upper pan Also called (in Britain and certain other countries) double saucepan