* WONGSHY. 139 



having received 15 gr. of solution of inferior indigo, prepared 

 as above directed, water is to be poured in until it assumes the 

 tint of the standard liquor. The difference in the quantity 

 of water required to produce a uniformity of shade in the two 

 liquids, denotes the ratio of the quality of the indigoes em- 

 ployed. For example, 20 pts. water were used for the stan- 

 dard solution, whereas the same quantity of the indigo under 

 test required only 15 measures to produce the same degree of 

 coloration : therefore the latter contains 25 per cent, (a^gths) 

 less of coloring matter than the former. 



The author gives the following results of certain essays with 

 solution of best Bengal indigo, = 20. 



Bengal, No. 2, quality 19 



" No. 3, " 7 



Java, No. 1, quality 19| 



No. 2, " 18 



Coloring -matter of Soorangee. — This material, extensively 

 used by the native Indians as a dye, is imported from Bombay. 

 According to Dr. Anderson, it is the root of the morinda 

 citrifolia. His examinations (Ch. Gaz. vi.) prove that it con- 

 tains a red coloring principle morindin, extracted by alcohol, 

 which is very similar to madder-purple both in physical and 

 chemical properties and in composition, though differing re- 

 markably as a dye. Its behavior to mordants is given in 

 detail in the original paper. 



Wongshy. — This new yellow dye, imported from Batavia, 

 according to Stein (Journ. f. Prac. Chem. 1849), consists of 

 the seed-vessels of a plant of the family of gentianse ; by tri- 

 turation with water it gives a reddish-yellow liquid which re- 

 tains its color even when largely diluted. Alcohol acquires 

 by digestion with it a bright-red tint. It yields an orange-color 

 to unmordanted woollen cloth ; cottons require to be mor- 

 danted. The color resists the action of soap, but is yellowed 

 by alkalies and reddened by acids, and fades by exposure tc 

 light. The details of the author's experiments are given in 

 the original paper. 



