This section is from the book "Mrs. Lincoln's Boston Cook Book", by Mary J. Lincoln. Also available from Amazon: Mrs. Lincoln's Boston Cook Book.
Remove the fat, and allow the white and shell of one egg for every quart of stock. If you wish to flavor the stock more highly, add half a saltspoonful of celery seed and the thinnest possible shavings from the rind of half a lemon.1 Add also the lemon juice, and more salt and pepper if needed. Mix celery seed, lemon, egg, etc. with the cold stock, and beat it well. If the stock be hot when the egg is added, the egg will harden before it has done its work. This is a point where many fail. Set it over the fire and stir it all the time, until it is hot, to keep the egg from settling. Then leave it, and let it boil ten minutes. By this time a thick scum will have formed, and as it breaks the liquid will be clear and sparkling, like wine, and darker than before. Draw it back on the stove, and add half a cup of cold water. Let it stand ten minutes, while you get your jar, colander, and fine napkin ready for straining. Wring your napkin out of hot water, and lay it over the colander. Put the finest wire strainer on the napkin and then pour it all through. This strainer will catch the scum and shells which would otherwise clog the napkin. Let it take its own time to drain; but if you must [ ] it, raise the napkin first at one corner, and then at another, and let the liquid run down to a clean place. This is better than squeezing. This is all ready to serve as a clear soup by simply heating to the boiling-point. Serve with it, in the tureen, thin slices of lemon, a glass of sherry, yolks of hard-boiled eggs, or delicate flavored force-meat balls; or put on each plate a poached egg, or a spoonful of grated Parmesan cheese.
1 Clear soup should be highly seasoned, as clearing destroys some of the strength.
In making soups from this stock, bear this fact in mind: Do not waste the stock by boiling in it any material which requires long boiling. Vegetables, rice, sago, tapioca, macaroni, vermicelli, etc., should be cooked separately and then added to the stock, which should be brought to the boiling-point.
The following are some of the principal varieties. These soups are all supposed to have no meat served with them. The broth is clear and thin, and every particle of vegetable or cereal should be distinct, except in the soups called Mixed Vegetable and Tomato.
Concise rules for Common Brown Stock and Consomme are given for the benefit of those who do not need to read all the preliminary remarks.
 
Continue to: