248 , INDIGO, \VOAD. 



air. This process appears to injure in some degree the durability 

 of the colour ; and it is preferable to apply the dye, when first 

 separated from the plant. The brilliant blue cloths of Africa 

 and China, which are superior in hue to those of any other part 

 of the globe, are produced in this manner. 



390. The juices of several plants, growing in the different 

 countries of the East, are used by the natives of those countries, 

 in the same manner as Indigo ; and might probably furnish a 

 good substitute for it, if prepared with sufficient care. The use 

 of Indigo as a dye, on a large scale, is comparatively recent. It 

 was not until long after the discovery of America, that it was 

 commonly employed in England ; and the use of it was forbidden 

 by the governments of some European countries, from the fear 

 that it would supersede the use of Wood, which was then very 

 extensively cultivated. This dye was known to the Ancient 

 Britons, who stained their bodies with it ; and it was the prin- 

 cipal blue dye; until the introduction of Indigo. Its colour is 

 much less lively than that of Indigo, but it is more durable ; 

 hence it is commonly employed in union with that and other 

 dyes, but seldom now by itself. Woad (I satis sativa) is culti- 

 vated in many parts of Europe ; and is grown in considerable 

 amount in Lancashire. Its stem is about three or four feet high, 

 and about half an inch in diameter ; it divides into many 

 branches, which are loaded with leaves. It is cut down with a 

 scythe, when the flowers are about to appear ; and afterwards 

 at intervals of about six weeks; three or four crops being 

 usually obtained in one year. The plants are first washed, and 

 then dried in the sun, without which they will begin to putrify, 

 their green colour turning black. They are then conveyed to a 

 mill, where they are ground into a paste. This paste is after- 

 wards subjected to several processes, for the purpose of drying 

 it. It is finally used nearly in the same manner as indigo ; 

 with which, indeed, its colouring matter, if extracted in the same 

 manner, is found to be nearly identical. 



391. A Violet hue is easily given to cloth, by mixing blue 

 and red dyes in any required proportion ; but there are some 

 plants, which yield a violet or purple dye, without any admix- 



