128 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



chemicals to the ground, to effect modifications in the characters of the 

 essential oils. 



It has been established that the peppermint plant, cultivated in soil to 

 which sodium chloride or sodium nitrate has been added, yields an oil 

 richer in ester than one cultivated without such addition. 



Processes of Extraction. 



The only method used by the ancients for the extraction of odours 

 from plants was that of maceration of the petals and the plant con- 

 taining the volatile oil in vegetable oil. After clarification, the resulting 

 ointment was used for the anointing of the body, or for such other 

 purpose as the perfume was required. At a later date, when the 

 process of distillation was introduced into Europe (probably about 

 1100 A.D.), it was gradually extended to the distillation of plants for 

 their oils. 



In some instances recourse was had to the process of fermentation 

 before distillation. This was done with juniper berries, sage, wormwood, 

 and other herbs, and in some instances the plant was even moistened with 

 alcohol before distillation. Of course a larger yield of so-called oil was 

 obtained, but apparently the distiller did not recognise that the oil was 

 diluted with alcohol. 



The volatile oil industry seems to have developed from very small 

 beginnings in the South of France in the fifteenth and sixteenth centuries, 

 with the distillation of lavender and rosemary oils, and the blending of 

 these and other oils to produce agreeable fragrant mixtures considerably 

 stimulated the industry. Perhaps the real perfume industry may be said 

 tj have had its origin in the preparation of Hungarian water in the 

 sixteenth century, which was an alcoholic distillate from fresh rosemary. 

 In the seventeenth century an alcoholic distillate made from balm and 

 lavender was known as Karmelite Geist. It was in 1725 than Johann 

 Maria Farina introduced his famous Eau-de-Cologne. 



The following are the processes now used for the extraction of perfume 

 from flowers : — 



1. Distillation by heat ;— fire or steam. 



2. Extraction from the petals or leaves by placing them on cold fats 

 {cnjieuragc) ; a process only used for the most delicate flowers, such as 

 tuberose and jasmine. 



3. Extraction by warm effusion on fat ; a process used for violets, 

 roses, &c. 



4. Extraction by various volatile solvents such as alcohol, petroleum- 

 ether, acetone, &c. 



5. Expression as used upon the skins of fruit (lemon, bergamot, 

 orange, &c.). 



Distillation. 



In connection with the first process, one cannot do better than use as 

 an illustration the method of distillation of lavender flowers as resorted 

 to on the hillsides in the districts of Grasse, Mitcham, and Ampthill 

 respectively. 



