Carlotta C. Greer, School and Home Cooking
“ From the results of Experiment 69 we know that an increased quantity of baking soda will not produce satisfactory results. Hence more carbon dioxide gas must be obtained by other means. Since baking powder consists of both baking soda and an "acid" material, it makes a desirable substance for additional leavening. A combination of baking soda, sour milk, and baking powder is therefore used for leavening some quick bread mixtures, especially those that contain only a small quantity of sour milk and no eggs. ”
