416 COLOURS. 



may be obtained from the gall of animals. It is 

 a very rich colour, but does not stand. 



Raw Terra Sienna^ is a native ochrous earth 

 brought from Italy. It is a fine warm colour, and 

 stands well. 



French berries. A liquor may be extracted 

 from these, which is useful as a stain for some 

 coarse purposes ; but it does not keep its colour. 



Turmeric root, and sqffro?i, may be used for si- 

 milar purposes. 



Ora7ige lake is the tinging part of annatto pre- 

 cipated together with the earth of alum. It does 

 not stand. 



Brown pinli is the tinging part of some vegeta- 

 ble substance precipitated upon the earth of alum. 

 It is of a fine rich greenish yellow, but does not 

 stand in water. 



Green Colours. 



There are few colours that are useful as greens ; 

 accordingly, it is the practice with artists, to form 

 their greens by the mixture of blue and yellow 

 colours. By varying these, a vast variety of" green 

 tints may be obtained. 



Sap green. This colour is the concreted juice 

 of the buckthorn-berries. It is never used in oil. 

 It is employed chiefly in flower-painting and co- 

 louring prints, he. 



Ve?Yl?gris. If plates of copper, moistened from 

 time to time with vinegar, be left exposed to the 

 air, they will be converted into a green oxyd, 

 Called verdigris : this is an imperfect oxyd of 

 copper, combined with a small portion of acetic 

 acid, carbonic acid, and water. It is prepared in 



