SECT. VIII. 



COLOURING MATTER. 40? 



The principal red colours are such as are found to Red. 

 exist in the root, stem, or flower, of the five follow- 

 ing plants : 1st, From the roots and stems of Rubia 

 tinctorum dried, bruised, and sifted, a powder is 

 obtained that is soluble in alcohol, and partly 

 soluble in water, and dyes cloth, by means of 

 proper mordants, either violet or red. Its red is 

 very beautiful, and it possesses also the singular 

 property of dyeing the bones of animals of a red 

 colour when mixed with their food.* 2dly, From 

 Lichen Roccella and parellus, dried and reduced 

 to a powder, and then macerated in water, a red 

 precipitate is obtained by muriate of tin that forms 

 a beautiful but perishable dye. But when it is ap- 

 plied to marble it stains it of a beautiful violet that 

 is permanent for years. 3dly, From the flowers of 

 the Carthamus tinctorius when treated with al- 

 kalies, a red colouring matter is extracted, which is 

 precipitated by means of acids, and from which 

 the rouge used by ladies is said to be manufactured, 

 by mixing it with the powder of talc. 4thly, From 

 Ctfsalpinia crista, generally known by the name 

 of Brazil wood, a colouring matter is also obtained 

 that dyes stuffs red that have been first impregnated 

 with alum, and forms lakes that are employed in 

 painting on paper. 5thly, From H&matoxylon cam- 

 pechianum, or wood of Campechy, a red colouring 

 matter is obtained resembling that of Brazil wood, 



* Du Hamel, Phys. des Arb. liv. v. chap. ii. 



