This section is from the book "The Epicurean", by Charles Ranhofer. Also available from Amazon: The Epicurean, a Complete Treatise of Analytical and Practical Studies on the Culinary Art.
Peel the squash and mince two pounds of the inside, with four ounces of onions, or else select young, tender turnips, peel and mince two pounds of these, or, cut some carrots so as to have two pounds of the reddest part; the turnips and carrots should be parboiled. Put six ounces of butter into a saucepan, and when hot, add one of the above vegetables chopped very fine, and after it is lightly fried without coloring, then moisten with two quarts of white broth, skim and continue to boil until thoroughly cooked, then drain, mash the vegetable to reduce it to a paste, and dilute with the stock it was boiled in; season with salt, sugar and nutmeg, and if too thick use more broth; thicken with egg-yolks, cream and fine butter. Compiegne croutons (No. 51), cut in quarter of inch squares, and dried in the oven, should be served as a garnishing.
Three ounces of butter worked with a small whip until perfectly white, then incorporate slowly into it two egg-yolks, two spoonfuls of sifted flour, salt, sugar and nutmeg; mix in with this three whites of eggs, beaten to a stiff froth, and poach in a slow oven, in some buttered dome-shaped molds; unmold and serve separately the same time as the soup.
Small chicken forcemeat and cream quenelles, laid through a cornet on a buttered pan and poached in boiling water, then drained and served with the soup.