To Preserve the Color of Vegetables.
The French cooks generally use carbonate of ammonia to preserve the color of vegetables. What would lay on the point of a pen knife, is mixed in the water in which the vegetables (such as peas, spinach, string-beans and asparagus) are boiled. The ammonia all evaporates in boiling, leaving no ill effects. They also say that it prevents the odor of boiling cabbage.
Mrs. M. F. Henderson.