From: The Thorough Good Cook

Sauces: 32. Hollandaise

As in the Sauce Blanche, mix a dessertspoonful of flour and four ounces of butter. Moisten with two-thirds of the water necessary to make the sauce. Let it boil for a few minutes, and take the saucepan off the fire. Mix, while stirring, five yolks of eggs well beaten with a little water. Put the sauce back on the fire, so as to cook the eggs, and as soon as these are done, take the saucepan off again. Then you must proceed as when making the Sauce Blanche, adding the juice of one or two lemons, eight ounces of butter, and the rest of the water. To make this sauce well, you must prepare it in a shallow saucepan which holds double the quantity which you need, so as to be able to stir quickly. when the sauce is ready, you shift it into a smaller saucepan to keep it warm, leaving the spoon in it, so as to stir from time to time. At the moment of serving, if too thick, add a little water and fresh butter.