i86 PLANT AND ORGANIC CHEMISTRY 



and stearic acids. They are frequently solid at ordinary tem- 

 perature, and their consistency depends upon the proportion 

 of oleic acid present. 



Commercial oils 1 frequently contain free acids; thus in palm 

 oil the free acid calculated as palmitic acid usually varies 

 from twelve to eighty per cent. The presence of free acid in 

 an oil is doubtless the principal if not the only cause of its 

 tendency to act on metals, and therefore seriously affects the 

 suitability of an oil for use as a lubricant. 



Before leaving the subject of vegetable oils, I wish to call 

 attention to the essential-oil industry in Grasse. 2 The world- 

 wide fame of this locality depends upon the essential oils of 

 plants which grow wild or are cultivated in the neighborhood. 

 The oil of lavender, rosemary, the garden thyme, of the 

 Labiatce family afford an important export industry of Grasse. 



The following quantities of oil are produced in Grasse every 

 year: From the lavender, 80,000 to 100,000 kilograms; from 

 thyme 40,000, and from rosemary, 20,000 to 25,000 kilograms. 

 The quantity sent out from Grasse probably meets the require- 

 ments of the whole world. Dalmatia only furnishes the oil of 

 rosemary and sends about 20,000 kilos of this essential oil into 

 the market; Grasse also sends forth each year oil from the 

 citrus species, especially oil of neroli, which is much esteemed. 

 Orris butter is distinguished above many other perfumes by 

 an agreeable softness and great permanence. One of the houses 

 in Grasse prepares four to ten kilograms yearly. Its value in 

 Grasse is 1,500 to 1,800 francs the kilo. Besides the wholesale 

 distillation of orange flowers and roses, some other aromatic 

 plants are occasionally worked up when needed, though not 

 to any great extent. 



The processes used for extracting these perfumes by the 

 methods of "infusion" and "enfleurage" are extremely in- 

 teresting and may deserve a passing notice. The fat used as 

 the basis of the "pommade" is selected from the best pig's 

 lard or beef suet. The melting, its mechanical purification, 



1 Commercial Organic Analysis, by A. H.Allen, Philadelphia, 1887, vol. i, 

 p. 28. 



2 F. A. Fluckiger, Amer. Jour. Phar., March, 1885, p. 131. 



