To perfume a powder with otto of roses, place it in a mixing machine, i.e. a revolving cylinder or barrel provided with ribs internally. Spray the scent into the powder and set the machine in motion until the scent has been disseminated through the whole. To disseminate the scent better, dissolve 1 part of the otto in 6 parts of spirit of wine, and use the mixed essence in place of the pure oil.