oils. ;;•:> 



ot which in water, it is precipitated by alum with 

 which it forms a yellow lake."' 



The BROWN colour of vegetables, is equally abun- 

 dant. It is obtained very frequently from the bark of 

 the Butternut and Walnut trees, from the Sumach and 

 various species of Oak, as well as from the nutgalls 

 which are found on the leaves of the latter. 



VEGETABLE OILS.— Fixed oils are usually ex- 

 tracted from the seeds', sometimes from the pulpy fruits 

 of their respective plants. Some of them are used as 

 food, some as medicine, and others in the preparation 

 of the most durable paints which the artist employs. 



OLIVE OIL is extracted from the pulpy fruit of the 

 Olive Olea Europea, a shrub which grows naturally in 

 the south of Europe, and the Almond which also grows 

 in Italy and Spain, yields an oil equally well known, 

 though perhaps less extensively employed. The se 

 cretions of the same vegetable are frequently various, 

 but it is worthy of observation, that the cotyledons of 

 its seeds are always nutritive and mild. The Poppy, 

 so famed for its narcotic properties, will serve to ex- 

 emplify the truth cf this remark, for the oil which is 

 extracted from its seed, is tasteless, inodorous and mild, 

 being used like Olive oil for food, and possessing noth- 

 ing of the narcotic properties of the plant from which 

 it is obtained. 



VOLATILE OILS are also extracted from various 



plants. They exist in the bark of the Cinnamon, in 



the leaves of Mint, Partridge-berry and Geranium, and 



in the flowers of Clethra, Jasmine and Rose. From 



these they may usually be obtained by distillation or 



expression, but the fiagranceof the Jasmine is best 



preserved by steeping its flowers in fixed oil, till it has 



acquired their rich perlume. 

 9 



