TANS AND DYES 235 



In propagating indigo the seeds are sown in rows about 2 

 feet apart. The flowers appear about 3 months from the 

 time of seeding. The plants are then cut and steeped in water 

 for 12 to 16 hours, after which the water is run off into an- 

 other vat where it is actively agitated for 2 or 3 hours until 

 the indigo forms by oxidation and settles to the bottom. 

 The water is then drained off, leaving the blue precipitate 

 which is cut into blocks and dried. In the experience of in- 

 digo planters in India it has been found that a yield of 20,000 

 pounds of green material per acre is satisfactory. The yield 

 for the rattoon crops is somewhat less. From 20,000 pounds 

 of green material about 500 pounds of indigo paste is obtained. 

 The best grade of indigo is obtained from Java. In Java it 

 has been demonstrated that indigo may be grown profitably 

 in combination with tea by planting the indigo as an intercrop 

 between the tea plants. After harvesting the indigo the plant 

 residues may be used as a fertilizer for the tea. 



The indigo plant is extremely hardy and, as already indi- 

 cated, will propagate itself as a weed even if totally neglected. 

 It has already been distributed throughout nearly all of the 

 tropical countries. It seems more than probable that the pres- 

 ent high prices of dyestuffs will bring about a revival of the 

 industry of producing natural indigo. 



HENNA 



Henna (Lawsonia alba) is a much branched shrub, native 

 of Persia, Egypt, Arabia, India, etc. The shrub bears oppo- 

 site oval leaves and at maturity reaches a height of 8 to 10 

 feet. The dyestufi henna is obtained from the leaves and 

 young shoots. The first clipping of young shoots with the 

 leaves may be made at the age of 3 years and clippings may 

 be made twice annually thereafter. The leaves are dried, 

 ground, and made into a paste with water. This material is 

 used by Oriental women as an orange cosmetic for the eye- 



