424 Select Plants for Industrial Culture and 



harvest of flowers is from the middle of May till nearly the middle 

 of June ; the gathering takes place before sunrise [Simmonds]. 

 From 12,000 to 16,000 roses, or from 250 Ibs. to 300 Ibs. of rose 

 petals, are required according to some calculations for producing a 

 single ounce of attar through ordinary distillation. The flowers 

 require to be cut just before expansion; the calyx is separated and 

 rejected ; the remaining portions of the flowers are then subjected 

 to aqueous distillation, and the saturated rose-water so obtained is 

 repeatedly used for renewed distillation, when on any cold place 

 the oil separates from the overcharged water and floats on the 

 surface, whence it can be collected after refrigeration by fine birds' 

 feathers. Rose-oil consists of a hydro-carbon stearopten, which is 

 scentless, and an elaeopten, which is the fragrant principle. But 

 some other methods exist for producing the oil ; for instance, it 

 may be got by distilling the rosebuds without water at the heat of 

 a water-bath, or by merely passing steam through the still. The 

 odor may also be withdrawn by alcoholic distillation from the 

 roses or be extracted by the " enfleurage " process. The latter is 

 effected by placing the flowers, collected while the weather is 

 warm, into shallow frames covered with a glass-plate, on the inner 

 side of which a pure fatty substance has been thinly spread. The 

 scent of the flowers is absorbed by the adipose or oleous substance, 

 though the blossoms do not come in direct contact with it ; fresh 

 flowers are supplied daily for weeks. The scent is finally withdrawn 

 from its matrix by maceration with pure alcohol. Purified eucalyp- 

 tus-oil can be used for diluting rose-oil, when it is required for the 

 preparation of scented soap. The essential oil of orange-peel might 

 similarly be employed as a vehicle. The Reiue Agricole lately 

 stated, that from various kinds of Roses about 30 millions Ibs. of 

 flowers are annually gathered for oil-distillation in Southern France, 

 the price being 2d. to 2|d. a lb. 



Rosa Damascene, Miller.* 



Orient. Allied to the preceding and the following species, also 

 largely used for the production of essential oil of roses. The 

 particular varieties used in Turkey are called by Dr. Dieck 

 trigintipetala and Byzantina ; the latter grows easily from cuttings 

 and produces long shoots, the former is flowering still richer even 

 in Germany, both have through him become articles of horticultural 

 commerce. Prof. Crepin reduces R. Damascena to R. Gallica:. 

 According to Dr. G. Dieck: R. alba (Linne) is also a variety of this 

 or a hybrid with R. canina, the latter prevailing, and it is this 

 white-flowered rose which largely furnishes the oil at Kezanlik. 

 The annual time of flowering extends over several months. 



Rosa Gallica, Linne. 



The French or Dutch Rose. Middle and Southern Europe, 

 South-Western Asia. Hardy to lat. 70 in Norway. The intensely 



