2 bunches of leeks, 1-1/2 pints of milk, 1 oz. of butter, 1 lb. of POTATOES, pepper and salt to taste, and the juice of a lemon. Cut off the coarse part of the green ends of the leeks, and cut the leeks lengthways, so as to be able to brush out the grit. Wash the leeks well, and see no grit remains, then cut them in short pieces. Peel, wash, and cut up the POTATOES, then cook both vegetables with 2 pints of water. When the vegetables are quite tender, rub them through a sieve. Return the mixture to the Saucepan, add the butter, milk, and seasoning, and boil the SOUP up again. Before serving add the lemon juice; serve with sippets of toast.
The Allinson Vegetarian Cookery Book, by Thomas R. Allinson (Year 1915)