The French cooks very generally use carbonate of ammonia to preserve the color of vegetables. What would lay on the point of a penknife is mixed in the water in which the vegetables (such as pease, spinach, string-beans, and asparagus) are boiled. The ammonia all evaporates in boiling, leaving no ill effects. They say also that it prevents the odor of boiling cabbage. It may be obtained at the drug-stores.