OILS 449 



per cent, of oil. It dries still more rapidly even than the linseed oil. It is prin- 

 cipally used for paints and varnishes, and from its lighter colour, it is often used for 

 white paints. 



Oil of the Hazd-nut. This is extracted from the seeds of the Corylus avcllana, 

 which yield about 60 per cent, of the oil. It is liquid, has only a slight colour, no 

 odour, and a mild taste. Its specific gravity at 69 Fahr. is 0'9242 ; at 14 Fahr. 

 it solidifies. 



Poppy Oil. This is expressed from the seeds of the common poppy (Papaver 

 somni/eruin), which grows wild in some parts of England, It is cultivated in very 

 large quantities in Hindostan, Persia, Asia Minor, and Egypt, for the sake of the 

 opium which is obtained from the capsules. It is cultivated in Europe for the cap- 

 sules, which are used in medicine, and for the oil extracted from the seeds. The oil 

 is obtained by expression from the seeds, which do not possess any of the narcotic 

 properties of the capsules. These seeds are sold for birds, under the name of maw- 

 seed. 



It is used sometimes for burning ; and, after treatment with litharge or subacetate 

 of lead, is used for paints. 



Hemp-seed Oil. The seed of the common hemp (Cannabis sativa) yield, by expres- 

 sion, from 14 to 15 per cent, of their weight of a fixed oil. It is obtained principally 

 from Russia, but the native places of the plant are Persia, Caucasus, and hills in the 

 north of India. The seeds are small, ash-coloured, shining bodies. They are de- 

 mulcent and oleaginous, but possessing none of the narcotic properties of the plant. 

 They are employed for feeding cage-birds, and it has been stated that the plumage of 

 certain birds, as the bullfinch and goldfinch, becomes changed to black by the pro- 

 longed use of this seed. When fresh this oil is greenish, but becomes yellow.by age ; 

 it has a disagreeable odour, and insipid taste. It is sometimes used for illuminating- 

 purposes, but, being a drying oil, it forms a thick varnish, and thus clogs the wick ; 

 it is used also in making soft soap, and in paints. When boiled with litharge or sub- 

 acetate of lead it forms a good varnish. 



Sunflower Oil. The seeds of the sunflower (Helianthus annuus) yield about 15 per 

 cent, of a limpid oil, having a clear yellow colour. It has an agreeable odour, and 

 mawkish taste. Its specific gravity at 60 is 0'9263 ; at 9 Fahr. it becomes solid. 

 It is sometimes employed as food, as well as for illuminating-purposes, and for making 

 soap. 



Castor Oil. The castor-oil plant has been known from the remotest ages. Caillaud 

 found the seeds of it in some Egyptian sarcophagi, supposed to have been at least 

 4,000 years old. Some people imagine it is the same plant that is called the gourd 

 in Scripture. It was called KpAruiv by the Greeks, and ricinus by the Romans. It is 

 a native of India, where it sometimes grows to a considerable size, and lives several 

 years. There appear to be several species of the Ricinus ; the oflicinal is the Ricinus 

 communis, or Palma Christi. 



The seeds are oval, somewhat compressed, about 4 lines long, 3 lines broad, and 

 1 i line thick ; externally they are pale grey, but marbled with yellowish-brown spots 

 and stripes. 



The oil may be obtained from the seeds by expression, by boiling with water, or 

 by the agency of alcohol. Nearly all that is consumed in England is obtained by 

 expression. See CASTOE OIL. 



Castor oil is said to bo adulterated sometimes with croton oil, to increase its 

 activity, this is a dangerous sophistication ; it is also mixed with some cheap fixed 

 oils. The latter adulteration has been said to be detected by the solubility of castor 

 oil in alcohol ; but, unfortunately, castor oil may contain as much as 33 per cent, of 

 another fixed oil, and yet be soluble in its own volume of alcohol (Pereira), this oil 

 possessing the property of rendering other oils soluble in spirit. 



Grape-seed Oil. The grape-stones (Vitis vim/era) yield about 11 per cent, of their 

 weight of a fixed oil, which is, when fresh, of a clear yellow colour, but becomes 

 brown by age. It has an insipid taste, and little or no odour. Its specific gravity at 

 60 Fahr- is 0'9202 ; at 3 Fahr. it becomes solid. It is not of much value for illumi- 

 nating purposes ; but in some southern localities it is used for food. 



Oil of the Pine and Fir trees. In the Black Forest, in Germany, an oil is extracted 

 from the cleaned seeds of the Pinus picea and P. abies. It is limpid, of a golden- 

 yellow colour, and resembles in smell and taste the oil of turpentine. Its specific 

 gravity at 60 Fahr. is 0'93; it only congeals at 22 Fahr. It is very fluid, and 

 dries rapidly. 



Oil of Camelina. This is extracted from the seeds of the Myagntm sativum. It is 

 of a clear yellow colour, with but little smell or taste, and dries rapidly by exposure 

 to the air.. 



The Oil of Belladonna-seeds. This oil is extracted in Wurtemberg from the seeds 



VOL. III. G G 



