Lemon Creams

From 1922:

Two tablespoonfuls arrowroot, 2 cupfuls boiling water, 1 small cupful sugar, rind and juice of two lemons, and whites of 3 eggs. Make the arrowroot with the boiling water, add the sugar and rub in the lemon rind and juice. Beat up the whites of the eggs to a stiff froth, mix the yolks with the arrowroot, then stir in the whites thickening over a slow fire, pour into a mould, then turn out and serve with cream.