126 



A GREEN DYE FROM CHINA. 



1856. 



Chemical 

 Characters. 



Rov. J. 

 Edkins. 



Process of 

 extraction. 



blue of considerable brilliancy. It is insoluble in water, rectified 

 spirit, or ether, whether cold or hot. With fixed alkalis, however, 

 a solution of an intense green colour is obtained. A solution 

 prepared by boiling ten parts of the dye with three parts of 

 carbonate of potash (KO, C0 2 ) has a brilliant bluish-green, and 

 possesses the following characters. The addition of an acid 

 occasions no precipitate. Solution of hypochlorite of soda 

 (Liquor sodce chlorinatce, P. L.), very sparingly added, changes the 

 green to blue, which speedily passes to purple and then to pink ; 

 a large addition of the reagent destroying the colour completely. 

 Solution of iodine produces the same changes from green to 

 pink. Sulphurous acid alters the green to a yellowish- brown. 

 Hydrochloric acid occasions no change in a solution of the dye ; 

 nitric acid renders it brown. 



This brief and superficial examination is almost all that 

 my small stock of the dye has permitted, but upon the arrival of 

 a larger quantity, I trust a complete investigation will be made. 



The following is the substance of the information before 

 alluded to, as obtained by the Eev. J. Edkins. 



The bark of two kinds of the tree called 



Luh-chae, literally Green-shrub, one kind growing wild, which is 

 known as the white, and another, which is cultivated, and called 

 the yellow, are used to obtain the dye. The white, or wild LtiJi- 

 chae, grows abundantly in the neighbourhood of Kea-hing and 

 Ningpo. The yellow is produced at Tsoh-kow-pang, where 

 about thirty men are employed in the manufacture of the dye. 

 This place is two or three miles west of Wang-teen, a town a few 

 miles to the south of Kea-hing. The dye is also prepared in 

 Hoonan and at Ningpo, but not so good. 



The process is as follows : The two barks are placed together 

 in iron pans and thoroughly boiled in water. The decoction is 

 left undisturbed for three days, after which it is placed in large 

 earthenware vessels, and cotton cloth prepared with lime is 

 dyed with it several times. After five or six immersions, the 

 colouring matter is washed from the cloth with water, and 



