9] VITAL IMPORTANCE TO MANKIND 275 



them. Their main uses are for scenting, flavouring, or medicinal 

 purposes — for example in the manufacture of perfumes, soaps, and 

 other toilet preparations, in cooking and the production of all 

 manner of foods and beverages, and for therapeutic, antiseptic, and 

 bactericidal purposes. Other uses are as clearing agents and solvents, 

 as insecticides and deodorants, and in such diverse products as 

 printer's ink and toothpaste, library adhesives and chewing-gum, 

 shoe-polish and tobacco. 



We have already dealt with the flavouring and medicinal sides, 

 and noted the industrial uses, of various essential oils, and shall be 

 concerned with insecticides, etc., in the next section ; here we 

 must mention some of the more important ' essentials ' used in 

 perfumes (or scents, as they are called in Britain). These often 

 highly-priced products commonly consist of blends of the essential 

 oil or oils in alcohol, usually with a less volatile fixative. Examples 

 are rose oil or otto (attar) of roses, obtained principally from flowers 

 of the Damask Rose which are distilled without delay after being 

 picked in the early morning just as they are opening ; orange 

 blossom oil (neroli), formerly obtained from citrous plants grown 

 for the purpose but nowadays often synthesized and used in cos- 

 metics, etc. ; lemon-grass oil, from the leaves of a particular Grass 

 and used in cosmetics and medicine ; oil of citronella, from another 

 member of the same genus and used in cheap perfumes and as a 

 deodorant and insect repellent ; geranium, distilled from the leaves 

 of various species of ' Pot Geraniums ' (Pelargoniums) and widely 

 used in making perfumes and soaps ; ylang-ylang, from the flowers 

 of an Asiatic tree and now said to be present in almost every perfume ; 

 cassie, from one of the Acacias ; cedarwood oil, from the Eastern 

 Red Cedar ; bergamot, from a type of Orange ; bay rum, from a 

 West Indian tree ; calamus, from the Sweet-flag ; camphor (in 

 spite of its solid form) ; lavender and rosemary which are used 

 extensively in eau-de-cologne and soaps ; and very many others. 

 Although numerous synthetic products are now available, most of 

 the best perfumes are still of botanical origin and in increasing 

 demand, the annual gathering of flowers for this purpose alone being 

 said to exceed 10,000,000,000 lb. (over 4^ thousand million kilos). 



Insecticides and Herbicides 



Although more than twelve hundred species of plants have been 

 reported to have some insecticidal or at least insect-repellent 



