603 



FARMERS' REGISTER 



[No. 11 



turpentine with muriatic acid gas (the gaseous sub- 

 etance procured from common salt fy the action 

 of sulphuric acid.) The camphor procured in 

 well-conducted experiments amounts to hall' of the 

 oil of turpentine used. It agrees with common 

 camphor in most of its sensible properties; but 

 differs materially in its chemical qualities and com- 

 position. It is not soluble without decomposition 

 in nitric acid. From the experiments of Gehlen 

 it appears to consist of the elements of oil of tur- 

 pentine, carbon, hydrogen, and oxygen, united to 

 the elements of muriatic gas, chlorine, and hydro- 

 gen. 



From the analogy of artificial to natural cam- 

 phor, it does not appear improbable that natural 

 camphor may be a secondary vegetable compound, 

 consisting of camphoric acid and volatile oil. 

 Camphor is used medicinally, but it has no other 

 application.* 



15. Fixed oil is obtained by expression from 

 seeds and fruits ; the olive, the almond, linseed, 

 and rape-seed, afford the most common vegetable 

 fixed oils. The properties of fixed oils are well 

 known. Their specific gravity is less than that of 

 water; that of olive and of rape-seed oil is -GIS; 

 that of linseed and almond oil -932 ; that of palm 

 oil -968; that of walnut and beech-mast oil -923. 

 Many of the lixed oils congeal at a lower tempe- 

 rature than that at which water freezes. They 

 ail require for their evaporation a higher tempera- 

 ture than that at which water boils. f The pro- 

 ducts of the combustion of oil are water and car- 

 bonic acid gas. 



From the experiments of Gay Lussac and 

 Thenard, it appears that olive oil contains, in 100 

 parts. 



Carbon - - 77-213 



Oxygen - - 9-427 



Hydrogen - - 13-360 



This estimation is a near approximation to 11 

 proportions of carbon, 20 hydrogen and 1 oxygen. 

 The following is a list of fixed oils, and of the 

 trees that aflbrd them. 



Olive oil, from the Olive tree ( Oka Europea), 

 Linseed oil, from the common and perennial Flax 

 (^Linum usitatissimum et perenne), Nut oil, from 

 the Hazelnut {Conjlus Avellana), Walnut {Jug- 

 lans regia), Hemp oil, from the Hemp (Canna- 

 bis saliva), Almond oil, from the sweet Almond 

 (j^mygdalus communis), Beech oil, li-om the com- 

 mon Beech (Fagus sylvatica), Rape-seed oil, fi-om 

 the Rapes {Brassica Napus et campestris), Poppy 

 oil, from the Poppy {Papaver somniferum), oil of 

 Sesamum,from the sesamum (^Sesamuvwrientale), 

 Cucumber oil, from the gourds ( Cucurbita Pcpo et 

 Melopepo), oil of Mustard (^Sinapos nigra et ar- 

 vensis), o\\ of Sunflower, from the annual and 

 perennial Sunflower {Ilelianthus annuus et peren- 

 nis), Castor oil, from the Palma Christi (/^iemws 

 co7nmunis). Tobacco-seed oil, from the Tobacco 

 (^Nicotiana Tabacum et rustica), Plum kernel oil, 

 from the Plum tree (^Prunus domestica), Grape- 



* From the researches of Dumas, it would appearthat 

 camphor is an oxide of campiiene, itself a compound 

 of carbon and liydrogen. — J. D. 



t From the researches of Chevreul and Le Canu, it 

 would appear that the fixed oils consist of two princi- 

 ples, — a tluid principle oleinc, and a solid one marga- 

 rine,— the proportions of which vary in dilferent in- 

 stances. — J. D. 



seed oil, from the Vine ( Vitis vinifera), Butter of 

 cacoa, from the Cacoa tree \^Theohroma Cacao)., 

 Laurel oil, from the sweet Bay tree (^Laurus 

 nobilis). 



The fixed oils are very nutritive substances ; 

 they are of great importance in their applications 

 to the purposes of life. Fixed oil, in combination 

 with soda, forms the finest kind of hard soap. The ' 

 fixed oils are used extensively in the mechanical 

 arts, and for the preparation of pigments and 

 varnishes. 



16. Volatile oil, likewise called essential oily 

 differs from fixed oil, in being capable of evapora- 

 tion by a much lower degree of heat, in being 

 soluble in alcohol, and in possessing a very slight 

 desrree of solubility in water. 



There is a great number of volatile oils, distin- 

 guished by their emell, their taf.te, their specific 

 gravity and other sensible qualities. A strong 

 and peculiar odor may, however, be considered as 

 the great characteristic of each species: the vola- 

 tile oils inflame with more facility than the fixed 

 oils, and afford, by their combustion, different pro- 

 portions of the same substances, water, carbonic 

 acid, and carbon. 



The following specific gravities of different vo- 

 latile oils, were ascertained by Dr. Lewis : 

 Oil of Sassafras 1094 

 " Cinnamon 1035 

 " Cloves 1034 



" Fennel 997 



" Dill 994 



" Penny Royal 978 

 " Cumin 975 



" Mint 975 " Turpentine 792 



" Nutmegs 948 



The peculiar odours of plants seem, in almost 

 all cases, to depend upon the peculiar volatile oils 

 they contain. All the perfumed distilled waters 

 owe their peculiar properties to the volatile oils 

 they hold in solution. By collecting the aromatic 

 oils, the fragrance of flowers, so fugitive in the 

 common course of nature, is as it were embodied 

 and made permanent. 



It cannot be doubted that the volatile oils con- 

 sist of carbon, hydrogen, and oxygen ; but no ac- 

 curate experiments have as yet been made on the 

 proportions in which these elements are combined. 

 The volatile oils have never been used as arti- 

 cles of food ; many of them are employed in the 

 arts, in the manufacture of pigments and varnish- 

 es ; but their most extensive application is as per- 

 fumes. 



17. Woody fibre is procured from wood, bark, 

 leaves or flowers of trees, by exposing them to the 

 repealed action of boiling water and boiling alco- 

 hol. It is the insoluble matter that remains, and 

 is the basis of the solid organized parts of plants. 

 There are as many varieties of woody fibre as 

 there are plants and organs of plants ; but they 

 are all distinguished by their fibrous texture, and 

 their insolubility. 



Woody fibre burns with a yellow flame, and 

 produces water and carbonic acid in burning. 

 When it is distilled in close vessels, it yields a 

 considerable residuum of charcoal. It is from 

 woody fibre, indeed, that charcoal is procured for 

 the purposes of life. 



The Ibllowing table contains the results of ex- 

 periments made by Mr. Mushet, on the quantity 

 of charcoal afforded by different wood : — 



