As the scientific revolution gathered steam in the nineteenth century, advocates of various healthy diet principles and cooking methods used science to justify their claims for new ways of cooking and eating. Dr. T. and Mrs. L.A. Hopkins were among these pioneers, passionately recommending the convenience of adding dry ingredients like baking soda and cream of tartar to flour in advance and keeping a quantity on hand for all household baking needs. They describe the superiority of their prepared flour mixtures (for breads, cakes, etc.) in scientific terms and tell how the interaction of liquids and gases creates lighter or heavier dough depending on the end product. The Hopkinses included extravagant claims for their “powders,” citing healthier baked goods, more efficiency in the kitchen, and less expense because fewer eggs and shortening are needed among the benefits. Recipes for a wide variety of baked goods using the flour mixtures are included, as well as rules for eating and lifestyle, advocating the avoidance of animal foods, spices, alcohol, strong tea and coffee; eating between meals; going to sleep soon after eating; and eschewing hard-to-digest foodstuffs, such as cheese, greasy meat, and raw fruit. No “exercise of body or mind,” or reading is advisable immediately after eating. This edition of Science in the Kitchen was reproduced by permission from the volume in the collection of the American Antiquarian Society, Worcester, Massachusetts. Founded in 1812 by Isaiah Thomas, a Revolutionary War patriot and successful printer and publisher, the society is a research library documenting the lives of Americans from the colonial era through 1876. The society collects, preserves, and makes available as complete a record as possible of the printed materials from the early American experience. The cookbook collection comprises approximately 1,100 volumes.