A correspondent writes: " Have you verified the recipe for Otto of Roses given on page 317 of G. M.? I am afraid the person who embarked in the oil of rose business, and used that process, would 'get left.' The quantity of volatile oil in the most fragrant roses is very minute, and 100 pounds of the petals yield but 3 drams (180 drops) of it by distillation. The recipe you give would yield a very fair rose water, but it would require the use of a microscope of high power to discover the globules of oil".